(X+y-3)2+(X-Y+6)2=0,X2-Y2的值为()
问题描述:
(X+y-3)2+(X-Y+6)2=0,X2-Y2的值为()
答
(X+y-3)2+(X-Y+6)2=0
X+y-3=0,x+y=3,
X-Y+6=0,x-y=-6,
X2-Y2=(x+y)(x-y)=3*(-6)=-18