Question

Factor r^3 +512
helpful hint :(a+b)(a^2-ab+b^2)

Answer 1

Use the sum of cubes formula a^3 + b^3 = (a + b)(a^2 - ab + b^2).

Here a = r and b = 8 (since 512 = 8^3), so

r^3 + 512 = (r + 8)(r^2 - 8r + 64).

You can check by expanding: (r + 8)(r^2 - 8r + 64) = r^3 + 512.