Question

已知x-y+3的绝对值与2（x+2y)的平方互为相反数,求x的平方+2xy+y的平方的值

Answer 1

|x-y+3|+2（x+2y)^2=0

x-y+3=0

x+2y=0

y=1,x=-2

x^2+2xy+y^2

=(x+y)^2

=1