A
B
C
D
E
We know that (x – y)^2 = x ^2 + y^2 – 2xyBTGModeratorVI wrote: ↑Thu Jul 23, 2020 6:34 amIf xy = 7 and x – y = 7, then x² + y² =
(A) 35
(B) 42
(C) 49
(D) 56
(E) 63
Answer: E
Source: GMAT Prep Now
The important thing to recognize here is that if we square (x - y), we get a x² term and a y² term. We also get an extra xy term, but that's okay, because we're given some information about the product xy.BTGModeratorVI wrote: ↑Thu Jul 23, 2020 6:34 amIf xy = 7 and x – y = 7, then x² + y² =
(A) 35
(B) 42
(C) 49
(D) 56
(E) 63
Answer: E
Source: GMAT Prep Now
Solution:BTGModeratorVI wrote: ↑Thu Jul 23, 2020 6:34 amIf xy = 7 and x – y = 7, then x² + y² =
(A) 35
(B) 42
(C) 49
(D) 56
(E) 63
Answer: E
