# How do you evaluate the function g(x)=2x+7 when x=3?

Dec 23, 2016

$g \left(x\right) = 13$

#### Explanation:

Whenever you're given a function, you simply plug in the $x$ value you're given and then calculate the result.

1. $g \left(x\right) = 2 x + 7$
2. $g \left(3\right) = 2 \left(3\right) + 7$
3. $g \left(3\right) = 13$

4. The idea of a function is that you are given a value and you just have to plug that in your function, like I mentioned above.

5. The other thing that you may come across is the problem will ask you to graph a certain function. For those, you can simply plug in random values into the function and come up with points. For example, with the function in the above question $g \left(x\right) = 2 x = 7$, plugging in $3$, gave us the result $13$. What that means is $\left(3 , 13\right)$ is a point on your graph. so you plug in different $x$ values and you get different results and those are all points on your graph.

Hope it helped (c: