Question

To factor 9x^2 - 4, you can first rewrite the expression as:

A. (3x-2)^2
B. (x)^2 - (2)^2
C. (3x)^2 - (2)^2
D. None of the above​

Answer 1

C. (3x)^2 - (2)^2

Explanation:

Each of the two terms is a perfect square, so the factorization is that of the difference of squares. Rewriting the expression to ...

(3x)^2 - (2)^2

highlights the squares being differenced.

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We know the factoring of the difference of squares is ...

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

so the above-suggested rewrite is useful for identifying 'a' and 'b'.