- 数学计算(a+2)(a
- (a+2)(a-1)+(1-a)(2a+3)请帮忙写出详细的运算过程。
- (a+2)(a-1)+(1-a)(2a+3)
先算加号前的:
(a+2)(a-1)
=(a+2)a-(a+2)×1
=a²+2a-(a+2)
=a²+2a-a-2
=a²+a-2
再算加号后的:
(1-a)(2a+3)
=(2a+3)×1-(2a+3)a
=2a+3-(2a²+3a)
=2a+3-2a²-3a
合起来:
a²+a-2+2a+3-2a²-3a
=a²+a+2a-2a²-3a+3-2
=a²+3a-2a²-3a+1
=a²-2a²+3a-3a+1
=a²-2a²+1
=-a²+1
=1-a²