# What is the equation of the line with a slope of 0.25 that passes through the point (-1 -8)?

May 26, 2018

$y = 0.25 x - 7.75$

#### Explanation:

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

•color(white)(x)y=mx+b

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

$\text{here } m = - .25$

$y = 0.25 x + b \leftarrow \textcolor{b l u e}{\text{is the partial equation}}$

$\text{to find b substitute "(-1,-8)" into the partial equation}$

$= - 8 = - 0.25 + b \Rightarrow b = - 8 + 0.25 = - 7.75$

$y = 0.25 x - 7.75 \leftarrow \textcolor{red}{\text{is the equation of line}}$

May 26, 2018

color(indigo)(x - 4y= 31

#### Explanation:

Point-slope form of equation is

$y - {y}_{1} = m \left(x - {x}_{1}\right)$

Given : $m = 0.25 = \frac{1}{4} , \left({x}_{1} , {y}_{1}\right) = \left(- 1 , - 8\right)$

$y + 8 = \left(\frac{1}{4}\right) \cdot \left(x + 1\right)$

$4 y + 32 = x + 1$

color(indigo)(x - 4y= 31