# How do you write the equation of a line that passes through point: (1, 9) and has slope 5?

Mar 22, 2018

$y = 5 x + 4$

#### Explanation:

$\text{the equation of a line in "color(blue)"slope-intercept form}$ is.

•color(white)(x)y=mx+b

$\text{where m is the slope and b the y-intercept}$

$\text{here } m = 5$

$\Rightarrow y = 5 x + b \leftarrow \textcolor{b l u e}{\text{is the partial equation}}$

$\text{to find b substitute "(1,9)" into the partial equation}$

$9 = 5 + b \Rightarrow b = 9 - 5 = 4$

$\Rightarrow y = 5 x + 4 \leftarrow \textcolor{red}{\text{is the equation of the line}}$