Factor: 27-(m+2n)^3

Question

I've tried it but my answer was incorrect.

Answer 1

recall that a^3-b^3 = (a-b)(a^2+ab+b^2)

You have

3^3 - (m+2n)^3
= (3-(m+2n))(3^2 + 3(m+2n) + (m+2n)^2)
= (3-m-2n)(9+3m+6n+m^2+4mn+4n^2)

I think I like the original way more . . .