Question

Factor completely 81x2 – 4
a. (2x – 9)(2x + 9)
b. (9x – 2)(9x – 2)
c. (9x – 2)(9x + 2)
d. (2x – 9)(2x – 9)

Answer 1

Yep, it is C

Answer 2

i assume that is 81*x^2-4 so

81*x^2-4

9^2*x^2-2^2

(9x+2)(9x-2)

Answer 3

The binomial can be factored using the difference of squares formula, because both terms are perfect squares. The difference of squares formula is a^(2)-b^(2)=(a-b)(a+b).
(9x-2)(9x+2)

Answer 4

thanks everyone.