计算 (2x-3y-1)(-2x-3y+1)
问题描述:
计算 (2x-3y-1)(-2x-3y+1)
答
(2x-3y-1)(-2x-3y+1)
=[-3y+(2X-1)][-3y-(2X-1)]
=(-3y)^2-(2X-1)^2
=9y^2-(4X^2-4X+1)
=9y^2-4X^2+4X-1