Question

How do you answer this question

Answer 1

Answer:

9x^2 -4

Step-by-step explanation:

(3x+2) (3x-2)

FOIL

first: 3x*3x = 9x^2

outer: 3x*-2 = -6x

inner: 3x*2 = 6x

last: -2*2 = -4

Add together

9x^2 -6x+6x -4

9x^2 -4

Answer 2

Answer:

B) 9x^2 - 4

Step-by-step explanation:

Use FOIL (first, outer, inner, last)

First: (3x) * (3x) = 9x^2

Outer: (3x) * (-2) = -6x

Inner: (2) * (3x) = 6x

Last: (2) * (-2) = -4

When you add up the terms, you get:

9x^2 + - 6x + 6x + -4

Simplify this to get:

9x^2 - 4

An easier way is to recognize that this is a difference of perfect squares question because the format is (ax + b) (ax - b).

(ax + b) (ax - b) always equals (ax)^2 - b^2, so:

(3x + 2) (3x - 2) = (3x)^2 - (2)^2 = 9x^2 - 4