Question

a的14次方—1因式分解

Answer 1

a^14-1
=(a^7-1)(a^7+1)
a^7-1=(a-1)(a^6+a^5+a^4+a^3+a^2+a+1)
a^7+1=(a+1)(a^6-a^5+a^4-a^3+a^2-a+1)