# How do you factor  s^2-9?

To factor ${s}^{2} - 9$, you will need to use the difference of two squrares. This property tells us that $\left({x}^{2} - {y}^{2}\right)$ can be rewritten as $\left(x - y\right) \left(x + y\right)$
In this case, ${s}^{2} - 9$ will become $\left(s - 3\right) \left(s + 3\right)$, which is the answer you are looking for.