初一数学 选择题我急啊!`~~~~~~`~`~
问题描述:
初一数学 选择题我急啊!`~~~~~~`~`~
若(x+y-2)^2+/x-y+3/=0,则x^2-y^2的结果是( )
A.5 B.-5 C.-6 D.-4
答
(x+y-2)^2+/x-y+3/=0
x+y-2=0
x-y+3=0
x=-1/2
y=5/2
x^2-y^2=1/4-25/4=-6
C