SAT Subject Test Mathematics Level 1

(C)

(D)

(E)

27 . If (x + y)^2 = (x – y)^2 , which of the following must be true?

(A) x   =   y

(B) x   =   –y

(C) x   =   0

(D) y   =   0

x   =   0   or  y   =

0

(E)