化简求职 3（a+1)^2-(a+1)(2a-1),其中a=1
问题描述：
化简求职 3（a+1)^2-(a+1)(2a-1),其中a=1
答
(a+1)^2-(a+1)(2a-1)
[提取公因式]
=(a+1)[(a+1)-(2a-1)]
=(a+1)(a+1-2a+1)
=(a+1)(2-a)
=(1+1)(2-1)
=2*1
=2
3(a+1)^2-(a+1)(2a-1)
[提取公因式]
=(a+1)[3(a+1)-(2a-1)]
=(a+1)(3a+3-2a+1)
=(a+1)(a+4)
=(1+1)(1+4)
=2*5
=10