Question

绝对值x-2+(x-y-1)的平方等于 0，那麽，-y-(x的平方+2y平方)=?

Answer 1

因为|x-2|与（x-y-1）²均大于等于0；所以可知x-2=0,x=2;x-y-1=0,y=1;

将x=2,y=1带入式-y-(x²+2y²)=-1-6=-7;

谢谢采纳！