How do you factor completely 121x^2 – 16?

Feb 26, 2017

See complete solution explanation below:

Explanation:

This problem is in form:

$\left(a + b\right) \left(a - b\right) = {a}^{2} - {b}^{2}$

Where ${a}^{2} = 121 {x}^{2}$ and ${b}^{2} = 16$

Therefore:

$121 {x}^{2} - 16 = \left(11 x + 4\right) \left(11 x - 4\right)$