Question

Factor: 81x2 - 49

Answer 1

This is a difference of squares problem \[x ^{2}-a ^{2}=(x+a)(x-a)\]

Answer 2

\[(9x)^2-(7)^2=[9x+7][9x-7].\]

Answer 3

81x^(2)-49

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-7)(9x+7)