Given a Vector addition and subtraction, how to find the Vector.

[shadow90]

Homework Statement

Given the following Vectors: A+B= x1i + y1j and A-B= x2i + y2j
what is A? and what is B?

The Attempt at a Solution

I wasn't really sure how to go about this problem. I tried setting one side to A and pluging it into the other eqn A.. however that made no sense to me.

 

[Simon Bridge]

That would work but try z1=A+B and z2=A-B, then what is z1+z2?
(do the A and B part as well as the i and j part)