Question

What is that factored form of r^27-s^30?

Answer 1

(r^9 - s^10) (r^18 + r^9 s^10 + s^20)Explanation:

Answer 2

`r^(27)-s^(30)=r^(9\cdor3)-s^(10\cdot3)=(r^9)^3-(s^(10))^3\\\\=(r^9-s^(10))[(r^9)^2+r^9s^(10)(s^(10))^2]=(r^9-s^(10))(r^(18)+r^9s^(10)+s^(20))\\\\Used:\\\\(a^n)^m=a^(n\cdot m)\\\\a^3-b^3=(a-b)(a^2+ab+b^2)`