计算(x+2y-3z)(x-2y+3z)+(2y-3z)²
问题描述:
计算(x+2y-3z)(x-2y+3z)+(2y-3z)²
答
(x+2y-3z)(x-2y+3z)+(2y-3z)²
=[x+(2y-3z)][x-(2y-3z)]+(2y-3z)²
=x²-(2y-3z)²+(2y-3z)²
=x²