(x-2)(x+2)-(x+1)(x-3)

来源:百度知道 编辑:UC知道 时间:2024/05/22 14:31:23
一定要过程1!!!!!

(x-2)(x+2)-(x+1)(x-3)
=x^2-2^2-(x^2-2x-3)
=x^2-4-x^2+2x+3
=2x-1.

(x-2)(x+2)-(x+1)(x-3)
=x^2-4-(x^2-2x-3)
=x^2-4-x^2+2x+3
=2x-1

(x^2-4)-(x^2-2x-3)=2x-1

=x^2-4-(x^2+x-3x-3)
=x^2-4-x^2+2x+3
=2x-1

很简单,可以用平方差公式
(x-2)(x+2)-(x+1)(x-3)
=x^2-2^2-(x^2-2x-3)
=x^2-4-x^2+2x+3
=2x-1.

(x-2)(x+2)-(x+1)(x-3)
解:原式=(X^-2^)-(X^-3X+X^-3)

去括号,得,
X^-2^-X^+3X-X^+3
=-1+3X-X^

注:^表示平方