Question

Factor completely 49x2 − 81. (1 point)

Answer 1

49x2 − 81

(7x-9) (7x+9)

Answer 2

For this case we have a difference of perfect squares of the form:

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

Applying to the given exercise we have to:

$a = 7x\\b = 9$

So, we have:

$49x ^ 2-81 =\\(7x) ^ 2- (9) ^ 2 =\\(7x + 9) (7x-9)$

Thus, the factorization of $49x ^ 2-81$ is given by:

$(7x + 9) (7x-9)$

Answer:

$(7x + 9) (7x-9)$