y -x =2 and y + x= -2 ,Then ( x+y)(x-y)=?
#19 (no calculator) from test 10
If a-b=119 and a-b=7, what is the value of a?
if x^2 – y^2 = x- y and x<y, what is the average (arithmetic mean) of x and y?
A) 0
B) 1/2
C) 1
D) x/2
E) y/2
How’s everyone else doing on this quiz?