5-7(a+1)-6(a+1)方
问题描述:
5-7(a+1)-6(a+1)方
答
5-7(a+1)-6(a+1)方
=[5+3(a+1)][1-2(a+1)]
=(3a+8)(-2a-1)
=-(3a+8)(2a+1)