# If g (x) = 3^2 - x + 17, then how do you find g (2)?

Jul 7, 2015

In case there is an error in the question, lets look at $g \left(x\right) = {x}^{2} - x + 17$

#### Explanation:

For $g \left(x\right) = {x}^{2} - x + 17$

It may be helpful to think of it this way:

$g \left(\textcolor{red}{x}\right) = {\left(\textcolor{red}{x}\right)}^{2} - \left(\textcolor{red}{x}\right) + 17$

To find $g \left(2\right)$, we will replace all of the $\textcolor{red}{x}$'s with $\textcolor{red}{2}$s.

$g \left(\textcolor{red}{2}\right) = {\left(\textcolor{red}{2}\right)}^{2} - \left(\textcolor{red}{2}\right) + 17$

We get:

$g \left(2\right) = {\left(2\right)}^{2} - \left(2\right) + 17$

$= 4 - 2 + 17$
$= 2 + 17$
$= 19$

That is: $g \left(2\right) = 19$

Note: I am convinced that the use of parentheses in the first step is a very good habit to develop.