How do you simplify (a+b)^3?

2 Answers

(a+b)^3

=(a+b)(a+b)^2

=(a+b)(a^2+2ab+b^2)

=a^3+3a^2b+3ab^2+b^3

Jun 28, 2018

a^3+3a^2b+3ab^2+b^3

Explanation:

(a+b)^3 is the same as (a+b)^2(a+b), so if we write it in this way, it becomes a much easier problem to solve.

(a+b)^2 is the same as (a+b)(a+b), and if we distribute the a and b to both terms, we'll get

a^2+2ab+b^2

We now have

(a+b)(a^2+2ab+b^2)

Again, we can distribute the a and b to all terms to get

a^3+2a^2b+ab^2+a^2b+2ab^2+b^3

This simplifies to

a^3+3a^2b+3ab^2+b^3

Hope this helps!