this post was submitted on 22 Jan 2024
2 points (100.0% liked)

Math Memes

3752 readers
44 users here now

Memes related to mathematics.

Rules:
1: Memes must be related to mathematics in some way.
2: No bigotry of any kind.

founded 2 years ago
MODERATORS
 
you are viewing a single comment's thread
view the rest of the comments
[–] BoxerDevil@lemmy.world 0 points 2 years ago (2 children)

Can someone smart explain it to dumb me

[–] odium@programming.dev 0 points 2 years ago* (last edited 2 years ago) (1 children)

Explanation: How did they get from

x + 2 = x - 2

to

(x+2)(x-2)=0?

That's not a valid step.

[–] PM_Your_Nudes_Please@lemmy.world 0 points 2 years ago* (last edited 2 years ago)

It’s not solvable using traditional algebra.

Typically you would try to get all of the variables on one side, and all of the numbers on the other.

So in this instance, you’d start by moving them around to get things together:
x+2 = x-2
x+2-x = -2
x-x = -2-2

But then you simplify, and cancel out any variables that need to be cancelled. In this case we see “x-x” so that cancels out to 0. And we see -2-2 which simplifies into -4. So the end result is:

0=-4

Which is obviously a nonsense answer. In the original post, homeslice did the first step wrong, moved everything over to the left incorrectly, (inadvertently setting the whole equation equal to 0) and the whole thing was downhill from there; Since the first step of their solution was wrong, everything behind it was also wrong.