What is the value of x^2 - y^2 ?
(1) x - y = y + 2
(2) x - y = 1 / (x+y)OG Quant
Review - 2nd Edition - DS-Question 46
This is an official question. OA and answer explanation is available.
My query is for second condition. How can we mutiply both sides by (x+y) unless it is specified that x+y is not equal to zero or x not equal to -y. Should we assume that denominator is not equal to zero in such GMAT questions ?