(x+2y)(3x-7y)2-4(x+y)2(x+2y)
问题描述:
(x+2y)(3x-7y)2-4(x+y)2(x+2y)
答
原式=(x+2y)[(3x-7y)2-4(x+y)2]
=(x+2y)[(3x-7y)+2(x+y)][(3x-7y)-2(x+y)]
=(x+2y)(5x-5y)(x-9y)
=5(x+2y)(x-y)(x-9y).