((x+2y)(x-2y)+4(x-y)的2次)/6x
问题描述:
((x+2y)(x-2y)+4(x-y)的2次)/6x
答
((x+2y)(x-2y)+4(x-y)^2)/6x
=[(x^2-4y^2)+(4x^2-8xy+4y^2)]/6x
=(5x^2-8xy)/6x
=(5x-8y)/6