x的八次方。先算(x+1)(x-1)得x的平方-1,然后(x的平方+1)乘以(x的平方-1)得(x的四次方-1)再用(x的四次方-1)乘以(x的四次方+1)得x的八次方。
(x+1)(x的平方+1)(x-1)(x的4次方+1)
=(x-1)(x+1)(x的平方+1)(x的4次方+1)
=(x²-1)(x²+1)(x^4+1)
=(x^4-1)(x^4+1)
=x^8-1
即x的8次方-1
(x+1)(x^2+1)(x-1)(x^4+1)
=[(x+1)(x-1)](x^2+1)(x^4+1)
=(x^2-1)(x^2+1)(x^4+1)
=(x^4-1)(x^4+1)
=x^8-1
(x+1)(x^2+1)(x-1)(x^4+1)
=(x+1)(x-1)(x^2+1)(x^4+1)
=(x^2-1)(x^2+1)(x^4+1)
=(x^4-1)(x^4+1)
=x^8-1
(x+1)( x^2+1)(x-1)( x^4+1)= (x+1) (x-1) (x^2+1) (x^4+1)= (x^2-1) (x^2+1) (x^4+1)= (x^4-1) (x^4+1)= (x^8-1)