Question

Use your knowledge of special cases to solve the problem.

( 3a - 2b )2 = ??

a) 9a^2 + 12ab + 4b^2

b)9a^2 - 4b^2

c)9a^2 - 12ab + 4b^2

Answer 1

C

Explanation:

We want to simplify:

`(3a-2b)^2`

Recall the perfect square trinomial pattern:

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

Let a = 3a and b = -2b. Thus:

`(3a-2b)^2=(3a)^2+2(3a)(-2b)+(-2b)^2`

Simplify:

`=9a^2-12ab+4b^2`

Our answer is C.