(a-1)(a^2 +a+1) - a^2 (a-8) 2a^3 +7 (x^2-x+1)(x+1) (b+2)(b^2-2b+4)-b(b^2-1) y^3-(y-3)(y^2+3y+9) ! ! 10 ! ,!

(a-1)(a^2 +a+1) - a^2 (a-8) = a³-1 -a³ +8a² = 8a² -1
2a^3 +7 (x^2-x+1)(x+1) = 2a³ +7(x³ +1) = 2a³ +7x³ +7
(b+2)(b^2-2b+4)-b(b^2-1)= b³ +8 -b³ +b = 8 +b
y^3-(y-3)(y^2+3y+9)= y³ -(y³ -27) = y³ - y³ +27 = 27