1) x^6-1 = (x^3+1)(x^3-1) = (x+1)(x^2-x+1)(x-1)(x^2+x+1)2) x^8-1 = (x^4+1)(x^4-1) = (x^4+1)(x^2+1)(x+1)(x-1) = (x^2+1)(x^2-x+1)(x+1)(x-1)(x^2+1)3) x^4-18x^2+81 = (x^2-9)(x^2-9) = (x-3)(x+3)(x-3)(x+3) = (x-3)^2(x+3)^2
1) x^6-1 = (x^3+1)(x^3-1) = (x+1)(x^2-x+1)(x-1)(x^2+x+1)
2) x^8-1 = (x^4+1)(x^4-1) = (x^4+1)(x^2+1)(x+1)(x-1) = (x^2+1)(x^2-x+1)(x+1)(x-1)(x^2+1)
3) x^4-18x^2+81 = (x^2-9)(x^2-9) = (x-3)(x+3)(x-3)(x+3) = (x-3)^2(x+3)^2