(a+1)(a-1)(a^2+1)-(a^4+1)的运算结果是_________

题目

(a+1)(a-1)(a^2+1)-(a^4+1)的运算结果是_________
2.(x-1)(x+9)=
3.(x+6)(x+10)=

答案

-2(a+1)(a-1)(a^2+1)-(a^4+1)
=(a^2-1)(a^2+1)-(a^4+1)
=a^4-1-a^4-1
=-2
(x-1)(x+9)=x^2+8x-9
(x+6)(x+10)=x^2+16x+60