TikTok is a bad math goldmine! Solving the equation x+2=x-2. Reddit r/sciencememes
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- čas přidán 5. 07. 2024
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Original post on Reddit: / qjsr7xycd4
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#math #algebra #mathbasics
Hes getting stronger.
He can manipulate the board by sinply tapping it with the back of his marker.
We must stop him before its too late
😂
One day he shall no longer have a need for markers, his mind is enough
Let's be honest, you can already see just by looking at the question that this will have no solution...
Yes, I can.
That's obvious, but apparently it isn't for some people, so they deserve a lengthy explanation.
This stupid comment has more likes than the comment below this, which has actual valuable information unlike this junk
(X+4) does not equal x
Who came up with it was for sure just writing down random numbers, the statement "a number plus two is equal itself minus two" is a paradox
Guy had the mental prowess to apply difference between two squares, but not enough to do the first step right💀💀
That's how you can tell that this is almost certainly someone yanking our chain. Most of the algebra is just to distract attention from the blatantly ridiculous first step.
Bros probably solve the 1st line, then ask chatgpt to solve the rest 💀
What he is showing first is the solution from the TikTok video. Then he proceeds to show how it is wrong.
@@cybore213 OC wasn't talking about bprp
@pegasoltaeclair0611 Thanks. Sometimes it's hard to figure out who the comment refers to. But I should have figured out that the OP was referring to the guy who posted the TikTok answer.
This is not math this is meth
😂
Either way, it's wasted brain cells.
My eyes are bleeding fron the proposed solution
I mean they literally could’ve just checked it, there is no way 2+2 = 2-2 (if you use sqrt4 which idk why they didn’t even simplify it down to just 2 but I digress)
-Remembers the negative square root
-Forgets division exists
The fact that he had zero on the right, not 1 implies he was mixing up subtracting with multiplication, not division.
No, he simply copied what tiktok gave as the answer and then explained why it is complete bullcrap.
The tiktok was a joke, literally.
I have a solution, change = to ≠ 😅
Surely,
The equation
x + 2 = x - 2
should be replaced with
x + 2 ≠ x - 2
another solution is changing = to >
x+2=x-2 (false)
x+2>x-2 (true)
Another solution, the equation is in Z/2Z
I love this comment. 😂
@@wqrwtrue dat.
That proposed solution is got to be a ragebait ,
Using Tiktok is already a signal for the lack of common sense
I hate how the first step is (x+2)(x-2)=0, which immediately implies x=±2, and then the TikTokker goes on to undo that and expand the quadratic out so that they can solve it by taking square roots instead. That almost bothers me more than the fact that the first step is completely bogus.
Not simplifying into 2 is probably intentional so that people won't just mentally check their solution and find out how garbage it is.
Bro got a degree in psychology but failed math 💀
I love the tap erase. Super tech white board ;)
Thanks!!
I got it from Amazon haha
@@adityagoyal7110
0-2=-2
0+2=2
-2=2
So no, its not correct
@@adityagoyal7110 aah yes 0 - 2 = 0+2 which would imply or -2 = 2
@@adityagoyal7110 Since when adding or subtracting to 0 gives back 0? Are you implying 0 is infinite?
It's really unnecessary to do anything past subtracting x on both sides, you got 2 = -2, a likewise always false statement like 0 = -4. What I wanna know is how somebody thought dividing (correction: multiplying) both sides by x - 2 would give 0 on the right side. 🤣🤣🤦🏾♂🤦🏾♂
Even worse, this was obviously multiplying both sides with (x-2).
That was not dividing both sides. That was multiplying the left side by (x-2) while SUBTRACTING (x-2) from the right side to give that zero.
What was done as the first step is this : (x+2) = (x-2) → (x+2)*(x-2) = (x-2) - (x-2) → (x+2)(x-2) = 0
@@KualinarNono, it was just dividing both sides by 1/(x-2). I don’t know what composition rules they’re working under where that equals 0 on the right hand side, but technically it was dividing both sides by 1/… just as much as it was multiplying by (x-2)
@@Tristanlj-555 Dividing can never reduce a value to zero. ONLY a subtraction can do that.
Then, a division by (x-2) would have made the left side into THIS : (x+2)/(x-2) NOT (x+2)*(x-2)
@@Kualinar I know that. I just finished my last exam, complex analysis for my first year of mathematics at Uni. I alluded to that jokingly by mentioning composition rules.
The very FIRST step of the proposed «solution» is totally wrong.
There are NO solution as this define two parallel lines.
The question goes like:
I love Math = I hate Math
To be precise, there is no solution in the real numbers or the complex numbers. But there are solutions in other number systems. For example, both the affine extended real number system and the projective real number system has a value infinity, denoted ∞ (or perhaps +∞ in the affine system). We have ∞+2 = ∞-2 = ∞ so ∞ is a solution. I'm sure there are other solutions in other number systems. Perhaps infinite cardinal numbers?
Integers mod 2 has infinite solutions :)
@@liamernst9626 That is an *excellent* answer! I wish I had thought of it. Of course, modulo 4 also works and has the advantage that "2" is still called 2 in that system.
@@rorydaulton6858🤔 this is essentially a question of whether two parallel lines can intersect at one point
@@vdm942no
This is why you should always plug your solution into the original equation to make sure it's correct.
You'll run into a problem here, the solution they got is x = 2 or -2. If you plug in -2 on the left and 2 on the right it technically works. Obviously you're supposed to do the same number for both x values but we're past the point of them doing the right thing.
@@jacobisbell9388 Yeah to be fair that makes sense.
Before I watch your video I'm going to say NO SOLUTION.
How can there be ?
I hate people who are bad at math, and think they are good at it. Even worse - people who know SOME math and do wrong things on PURPOSE and then brag about it just to get FREAKING COMMENTS OF PEOPLE WHO GET MAD AT THEM BUT DON'T UNDERSTAND THAT THIS IS EXACTLY WHAT THEY WANT
Yea I’m no calculus major, but I know enough about (X)’s to put all X’s on one side and everything else that you can on the other. And that gets 0X=-4, which is about as wonky as the first question.
I am sure that if you would stop at 0X=-4, someone would say X = -4/0
@@tundcwe123i mean now that you mention it..... infinity + 2 = infinity - 2.
That is if you consider dividing by zero to equal infinity, and not undefined
"x+2=x-2"
"No it doesn't"
I will be born tomorrow and i solved this,how could tiktokers not
This is why i had a high school teacher who said he doesn't like calling it bringing to the other side because it causes confusion like that
You need to be doing the same thing on both sides, so he emphasizes that point in the equality so none of us do such a bjg mistake
2:41 divide by x-2
😊
In complex numbers, |x - 2| = |x + 2| is fairly obviously just any purely imaginary number i.e. Re(x) = 0. But that's the only way to get anything even approximating a solution.
I immediately saw both equations as straight lines with gradient 1 and intercept 2 and -2 (y=mx+c).
So two parallel straight lines; therefore no solution.
Playing with the equation -> x+2 = x-2
Subtract (x-2) from both sides -> x-x+2+2 = 0 -> 4 = 0, which is categorically false so the original equation can't exist.
Now to watch and see what bprp does.
The same goes to Facebook reels, a lot of times some random math questions pop up and the answer is wrong
The OP caption is indeed accurate.
I was so focus on the second line, wondering why would he go through all the other steps to find the solutions, that I completely ignored the obvious issues before that... Guess I just didn't want to see it. 😂
I would really like that tiktok commentator to explain his second step, bro accidently entered 4th dimension lmao☠️
You are SOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO right!
TikTok should be banned!!
If you thought about the initial equation even a little, you can easily see how it's ridiculous. What is a number, where you could either add or subtract 2 from it, and the result is still the same? What is a number where it wouldn't matter whether you added or subtracted anything, it's still the same? And there isn't any real solution.
We have: x = x + 4
Now substitute x into x:
x = (x + 4) + 4
x = x + 8
x = x + 16
…
And similarly this can be done by first subtracting 2 over,
ie, x = x - 4
The only way adding these finite quantities can work without affecting anything is if x is +/- ♾️
love these vids.
the gentleman has as much talent for math as a brick has for swimming
Can you teach me how can I sove this problem, please?
sqr(a)+sqr(ab)+sqr(abc)=12
sqr(b)+sqr(bc)+sqr(abc)=21
sqr(c)+sqr(ac)+sqr(abc)=30
Find: (a^2 + b^2 + c^2)
Tried but couldn’t solve it. I’d love a video on this problem
(a^2 + b^2 + c^2) is below the first three equations and on the right side of 'Find:'. Thanks me later.
There's probably a better approach but you could solve it by brute force. I suggest substituting √a, √b and √c by u, v, and w just to get rid of the square roots.
You'll then get this system of equations:
u + uv + uvw = 12
v + vw + uvw = 21
w + uw + uvw = 30
Three equations with three variables should yield solutions.
Then, plug the solutions into the last term. (Just remember that it will have to be u⁴ + v⁴ + w⁴.)
I had WolframAlpha do the work for me. There are three sets of solutions. the sum of squares that we are supposed to find can be either 2433, 10002, or 312688557441/384160000.
Like I said, maybe there's a better way but the old-fashioned way should work.
If I had to do it by hand, I'd start by subtracting the second from the first equation:
u + uv - v - vw = -9
We can isolate u by factoring it out and bringing the other stuff on the right hand side:
u (1+v) - (v+vw) = -9
u = (v+vw+9) / (v+1)
it took me some time and I must have made a mistake in my regular scholarly attempts, but then it jumped at me: it works for a = 1, b = 1, c = 100, so your result is 10002.
method: first substitution for those ugly sqrts: A = sqrt(a), B = sqrt(b), C = sqrt(c), so you get
A + AB + ABC = 12
B + BC + ABC = 21
C + AC + ABC = 30
now you see every next equation is 9 bigger, so it is as if you subtract 1 and add 10. and this really works if A = 1, B = 1, C = 10 so you get
1 + 1 + 10 = 12
1 + 10 + 10 = 21
10 + 10 + 10 = 30
A^4 + B^4 + C^4 = 1 + 1 + 10000 = 10002
@@popularmisconception1 Thank you, I liked your idea, but you found the answer by guessing.. Can we solve it by mathematical steps?
I was like.. is this a transfer function? Lmao
You can easily see that there is no solution
This must be from Terrance Howard's advanced thesis. 😂😂
We can prove that equation has no solution
Step 1:- write the equation in this form x+2/x-2=1
Step 2:- apply compendo and dividendo and we get
x/2=1/0
And we all know that 1/0 is undefined
With the first solution I was like, what has gone wrong with me, if this is math then I have actually forgot it all. I thought the doctor approved it already since he wrote it 😂😂
Sono molto curioso di questo esperimento 😊 grande Vito🎉
I was pulling my hair 1st time I saw the 1st step but more I looked at it the worse it got since in the 1st step alone made at least 3 different errors which I didnt know was even possible... until now
The ans is infinity
2:10 don't forget to consider the domain of x, x can't be 2 after dividing (x-2)
Yiu can also look at both sides as 2 linear function, since m is 1 for both functions the lines never meet, and thus there are no values for x of which the statement is true.
Good video. Thank you.
Thank you too!
the solution is super simple. subtract 2 from both sides to get x=x-4, then divide both sides by x to get x/x = 4, then take the derivative of everything to get 1/1 = 0. multiply both sides by x to get x = 0, and boom its solved
if only those tiktok user saw that both sides have 1x...
This is unrelated but could you please explain why x! = 0 has no solutions (even using gamma function in the complex plane).
My guy didn't even use the zero product property after his egregious step of moving the x-2.
I think commenters are forgetting that this is a channel for students as well, students who might be struggling with algebra. There are many ways to immediately convince yourself that the problem is unsolvable, e.g., the equations are parallel lines in Euclidean space. If you know what’s going on here, maybe don’t dunk on the folks who don’t. They’re often made to feel dumb in class enough already
Always check your answer. OP could see that he messed up somewhere by concluding that 4=0
I prefer to have my students think about the problem. I would ask can you think of a number that when you add 2 to it or subtract 2 from it you get the same result. The answer is obviously no and hence no solution.
There is also obviously no number that sin(x) = 2, and yet there are interesting complex solutions
There’s actually a solution. Just require limits.
x+2 = x-2
x+4 = x
1+4/x = 1
4/x = 0
If we take the limit as x->infinity
lim[x->+-infty] 4/x = 0
Although the main point is that the original post’s method is basically just bad practice on mathematics
x+2=x-2
x+2-x+2=0 At this point, I almost said "all real numbers" then I realized that's a PEMDAS issue. Actually:
x-x=0, 2+2=4
0=4, therefore no solutions.
First off it has no solution, and then the comment under it has a “solution” that not only has almost nothing to do with the question, it’s also just bad…
I just added 2 to both sides, got x+4 = x and I knew THAT isn't possible, so 'no soluitions'. done.
I mean using basic logic, a number PLUS 2 CANNOT be equal to the same number MINUS 2.
I dunno. If x = infinity, is there really any difference x-2 and x+2? Aren't both results infinite?
@@JanBruunAndersen infinity isn't a number.
Where do a 45° line that intercepts the y-axis at 2, and another 45° line that intercept the y-axis at -2, intercept each other?
In other words, where do 2 distinct parallel lines intercept each other?
(x+2) = (x-2) : multiply by (x-2)
(x+2)(x-2) = (x-2)^2 : (a+b)(a-b)=a^2-b^2 ; (a-b)^2 = a^2 +b^2 -2ab
x^2-2^2 = x^2+2^2-2*2x
x^2-4 = x^2+4-4x : subtract (x^2+4) from both sides of equation
x^2-x^2-4-4 = -4x
-8 = -4x : divide by -4
2 = x : reorder
x = 2 : Answer
(x+2) = (x-2) : multiply by (x+2)
(x+2)^2= (x-2)(x+2) : (a+b)^2=a^2 +b^2 +2ab ; (a-b)(a+b)=a^2-b^2
x^2+2^2+2*2x = x^2-2^2
x^2+4 +4x = x^2-4 : subtract (x^2+4) from both sides of equation
x^2-x^2+4-4 +4x= -8
4x = -8 : divide by 4
x = -2 : Answer
If your answer is 2 and the first step you do is multiply by (x-2), you multiply by 0. Then of course you will get a valid answer. Same for the 2nd try. Your answer is -2, so multiplying by (x+2) in the first step means you multiply by 0, too.
(x+2) = ( x-2) : multiply by x
x²+2x = x²-2x : substract x²
2x = -2x : +2x
4x=0
x=0
So another answer. NO. Same reason as in my above comment.
If you bring x-2 to the othher side, ou woud *not* get (x+2)(x2)=0 but x+2--(x-2)=0, which can be rewritten to x+2-x+4=0, which gives 2+2=0 and 4=0, which is a contradiction in realnumbes as welll as in compex numbers. So there is no reaor compex sollution. How can soeone thin, there a be a rea solution?
I figured out it was impossible so fast using 8th grade algebra.
x+2=x-2
add 2 to both sides
x+4=x
False, but you can continue by subtracting x from both sides
4=0
4≠0
Just the other direction of this guys final proof
"What’s wrong with this?"
Ummm. Everything?
Those answers don’t even work if plugged back in 😂
The empty identity for multiplication is 1 anyway so it should at least be (x+2)(x-2)=1
And you can already find x from that factored equation because you can just set each one to 0
What an egregious waste of time
I showed this problem to my 9-year old little cousin. Obviously, he didnʼt understand a thing.
Then, I asked “If I give you something, is it the same as if I take that same something from you?”; he quickly answered “Of course not!!!”.
0.
Make each side of the equation a function and compare X coefficients.
Two linear functions with the same slope cannot intersect unless they are the same function.
If f(x) = m1x + b1
and g(x) = m2x + b2,
x = Ø where m1x = m2x AND b1≠ b2.
But if f(x) = g(x), x = R (infinitely many Real solutions from -inf to +inf).
Reminds me of one time I fked up so bad in an exam I got to the point where 0 = 2 😍
It was a logarithmic equation too 😭
Is there complex solutions ?
(x+2)/(x-2) Can we use componendo and Dividendo in this?
There is a solution. If x is a member of the cyclic group defined by modulo 4, then the solution is x=2, and x-2 = x+2 = 0.
Even the solution for (x+2)(x-2)=0 Is ridiculously complicated. The polynomial is already factorized.
Move x to the left side, we have x-x+2=-2, then 2=-2, contradiction, done.
Surprisingly, TikTok didn't tell that 0 = -4 🤭
Graphically, lines are parallel with equal slopes, lines never intersect, no sol.
They even put the square root of 4 instead of 2😭
Only infinity could satisfy this equation but infinity is not a number
We have,
x + 2 = x - 2
=> (x + 2) /x = (x - 2) /x, x ≠ 0
=> 1 + (2/x) = 1 - (2/x)
=> 2/x = - (2/x)
=> 2/x + (2/x) = 0
=> 4/x = 0
4/x cannot be zero but it tends to zero as x tends to infinity.
The solution of This Equation does not exist.
Just substract x from both sides and you get 2 = -2 and you have the answer.
X here represents a quantum value, it is simultaneously 2 and -2 at the same time.
x + 2 = x - 2
x = x - 4
4x = 4x - 16
4 = 4 - 16/x
0 = -16/x
16/x = 0
x = ±∞
my approach was almost the same :
x+2-2 = x - 2-2
=>x = x - 4
=>x-x = x -x - 4
=>0 = -4(The input is a contradiction: it has no solutions)
Exactly!
x is in a quantum wave state oscillating between -2 and +2, entangled with itself so that when it is in one state on one side of the equation, it is in the corresponding other state on the other side of the equation.
So the solution is: 0 = 0 superposed with 4 = -4.
🤪
I'm more confused as to why the problem was posted on r/sciencememes instead of r/mathmemes
Lim (x->inf) [(x+2)/(x-2)] = 1, so lim (x->inf) (x+2) = lim (x->inf) (x-2). Ta-da!
/s obvs xD
One can understand by these are two parallel lines having slope 1 so it don't intersect each other so no there is no solution
You can substitute pretty much any word for math in the statement "TikTok is a bad ____ goldmine" and it will be accurate.
You can clearly see that both lines are parellel to each other and by definition, no solution.
The question was to find x, so...
x+2 = x-2 | -2
x = x-4
Let's be honest, let's be a bit logical. We can't have something upon which adding or substracting a number we get the same real number, hence there's no finite real number and that is for sure
dawg why did bro do subtraction but multiplication 😭
love is answer to everything, x should equal love
The first step performed by this tiktoker is wrong, where he was going would be (x+2)/(x-2)=1 which wont get you any closer to a solution. Basic algibra states
x-x +2 = x-x -2
+2 = -2
no solution
The fact that it didn't even said 2 as sqrt(4)..
Funnily enough, it has a solution x=1 in {N mod 2}. Just kidding, there's no 2 in {N mod 2}: there's only 0 and 1.
shouldn't it be obvious to anyone that there is no number where you can add two and subtract two and get the same result?
How did this turn into multiplication...