Simplify the following expression. (x + 6)3

Question

possible choices are;

216x^3 or x^3+216 or x^3+18x^2+108x+216 or x^3+18

Answer 1

You mean (x+6)^3, right?

That's (x+6)(x+6)(x+6)

Do two of the (x+6)s first:

(x+6)(x+6)

FOIL

x^2+6x+6x+36

x^2+12x+36

Now the third (x+6)

(x^2+12x+36)(x+6)

In the x+6, the x hits each thing in (x^2+12x+36), then the 6 hits each thing in (x^2+12x+36).

x(x^2+12x+36) + 6(x^2+12x+36)

x^3+12x^2+36x + 6x^2+72x+216

x^3+18x^2+108x+216

Comments

Thank you so much John Perkins