1.(x+5)^2-(x-5)^2-(2x+1)(-2x-1)

问题描述:

1.(x+5)^2-(x-5)^2-(2x+1)(-2x-1)
2.(a+1)(a-1)(a^2+1)(a^4+1)(a^8+1)

(x+5)^2-(x-5)^2-(2x+1)(2x-1)
=x^2+10x+25-x^2+10x-25-(4x^2-1)
=20x-4x^2+1
(a+1)(a-1)(a^2+1)(a^4+1)(a^8+1)
=(a^2-1))(a^2+1)(a^4+1)(a^8+1)
=(a^4-1)(a^4+1)(a^8+1)
=(a^8-1)(a^8+1)
=a^16-1