（a+1)(a+3)(a+5)(a+7)(a+15)过程也要给我,
问题描述：
（a+1)(a+3)(a+5)(a+7)(a+15)过程也要给我,
是（a+1)(a+3)(a+5)(a+7)+15
答
(a+1)(a+3)(a+5)(a+7)+15 =[(a+1)(a+7)]*[(a+3)(a+5)]+15 =[(a^2+8a)+7]*[(a^2+8a)+15]+15 =(a^2+8a)^2+22(a^2+8a)+120 =[(a^2+8a)+10]*[(a^2+8a)+12] =(a^2+8a+10)*(a^2+8a+12) =(a^2+8a+10)*(a+2)*(a+6)