Question

((x-y)/2)+y, please explain how to get the answer

Answer 1

What exactly are you looking for? The value of x?

Answer 2

what is the question? what is the instruction on you book say?

it's like saying this:
what's the answer to x+y....

Answer 3

Anyway, if you're looking for the value of x, it should be like:

(x-y)/2 + y = 0
(x-y)/2 = -y Transpose y to the other side
2[(x-y)/2] = (-y)2 Multiply both sides by 2 and cancel the denominator 2
x-y = -2y
x = -y Transpose -y to the other side, which makes it +y and add to -2y

Now since x= -y, just substitute that one to the original equation

(-y-y)/2 + y = 0

^Not sure if that one's right. I didn't kinda understand your question. :))