(x+y)的平方-(x+y)(x-z)+(x+y)(y+z)
问题描述:
(x+y)的平方-(x+y)(x-z)+(x+y)(y+z)
答
原式=(x+y)²-(x+y)(x-z)+(x+y)(y+z)
=(x+y)[(x+y)- (x-z)+ (y+z)]
=(x+y)[x+y-x+z+y+z]
=(x+y)(2y+2z)
=2(x+y)(y+z)