若|x+y-1|与(x-y+3)的平方,互为相反数,则(x+y)(x-y)
问题描述:
若|x+y-1|与(x-y+3)的平方,互为相反数,则(x+y)(x-y)
答
|x+y-1|+(x-y+3)的平方=0 所以x+y-1=0,x-y+3=0,所以x+y=1,x-y=-3 (x+y)(x-y)=1*-3=-3
若|x+y-1|与(x-y+3)的平方,互为相反数,则(x+y)(x-y)
|x+y-1|+(x-y+3)的平方=0 所以x+y-1=0,x-y+3=0,所以x+y=1,x-y=-3 (x+y)(x-y)=1*-3=-3