[(x+2y)(x-2y)-(x-2y)^2+8y(x+y)]除以4x=
问题描述:
[(x+2y)(x-2y)-(x-2y)^2+8y(x+y)]除以4x=
答
[(x+2y)(x-2y)-(x-2y)^2+8y(x+y)]/4x
=[x^2-4y^2-x^2-4y^2+4xy+8xy+8y^2]/4x
=12xy/4x
=3y