化简(x+2)(x-2)-(x-1)^2
问题描述：
化简(x+2)(x-2)-(x-1)^2
答
打开：原式=x^2-4-x^2+2x-1=2x-5
答
原式=x^2-4-(x^2-2x+1)
=x^2-4-x^2+2x-1
=2x-5
答
(x+2)(x-2)=x²-4
(x-1)^2=x²-2x+1
所以(x+2)(x-2)-(x-1)^2 =x²-4-(x²-2x+1)=x²-x²-4+2x-1=2x-5
答
(x+2)(x-2)-(x-1)^2
=x²－4－（x²－2x＋1）
=2x－5
答
(x+2)(x-2)-(x-1)^2
=(x^2-4)-x^2 +2x-1
=2X-5
答
(x+2)(x-2)-(x-1)^2
=x²-2x+2x-4-x²+1
=x²-x²-2x+2x-4+1
=-3