Anna and Belle are asked to solve - 2x - 15 = 6x + 9. Identify where one of them made an error.

Ok so first you need to identify what you are looking for ... you need to find x.

to do that you need toge it on one side. so cancel out the "-2x" on the left side by adding 2x (on both sides, don't forget you add common variables). now you should have something like this ...

-15=8x+9

now all you have to do is get rid of the 9 by subtracting 9 on both sides

you should have

-24=8x

With that, all you have to do now is divide 8 into both sides and it should look like a fraction now

-24/8=8x/8

the 8x/8 will cancel out the 8 and you will have

-24/8=x

Simplify that and you should get

-3=x

need me to explain it with fewer words?