How do you answer this question
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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:
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