化简(x-2y)平方-(2x-y)(-2x-y)+(x-5y)(x+2y)
问题描述:
化简(x-2y)平方-(2x-y)(-2x-y)+(x-5y)(x+2y)
答
(x-2y)²-(2x-y)(-2x-y)+(x-5y)(x+2y)
=x²+4y²-4xy-y²+4x²+2xy-5xy-10y²=6x²-7y²-7xy