Question

平方差公式的内容（最后两题了,） 计算：（a+1)(a-1)(a²+1)(a四次方+1)(a八次方+1)

Answer 1

（a+1)(a-1)(a²+1)(a四次方+1)(a八次方+1)

=(a²-1)(a²+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

(-2a+b)(3a-b)-(a+b)(a-b)

=（-6a²+5ab-b²）-（a²-b²）

=-7a²+5ab

a=1/2,b=-1

=-7*(1/4)+5*(1/2)*(-1)

=-7/4-10/4

=-17/4