1) x^3-1 = $x-1$$x^2+x+1$ 2) 27+a^3 = $3+a$$9-3a+a^2$ 3) 216-y^3 = $6-y$$36+6y+y^2$ 4) 1/8a^3+b = $1/2a+b$$1/4a^2-1/2ab+b$ 5) a^6-8 = $a^3-2$$a^3+2$ 6) a^3b^3-c^3 = $ab-c$$a^2{b}^2+abc+c^2$ 7) a^-b^15c^18 = $a-b^5{c}^6$$a+b^5{c}^6$ 8) 125c^3d^3+0.008b^3 = $5cd+0.2b$$25c^2{d}^2-1.6b^2$

1) $x-2$$x^2+2x+4$ = x^3+2x^2+4x-2x^2-4x-8 = x^3+4
2) $2a+3b$$4a^2-6ab+9b^2$ = 8a^2-12ab+18b^2+12a^3-18a^2b+27ab^2