Question

x的平方+2xy+y的平方分之4y的平方-x的平方÷2x的平方+2xy分之x-2y,

Answer 1

=-(x+2y)(x-2y)/(x+y)² ×2x(x+y)/(x-2y)

=-2x(x+2y)/(x+y)

=-(2x²+4xy)/(x+y)