# How do you find the slope-intercept of y = - 4x?

Jun 20, 2016

slope $= - 4$
y-intercept $= 0$
(x-intercept $= 0$)

#### Explanation:

The general slope-intercept form is
$\textcolor{w h i t e}{\text{XXX}} y = \textcolor{g r e e n}{m} x + \textcolor{b l u e}{b}$
with a slope of $\textcolor{g r e e n}{m}$ and a y-intercept of $\textcolor{b l u e}{b}$

$y = - 4 x$ is equivalent to $y = \left(\textcolor{g r e e n}{- 4}\right) x + \textcolor{b l u e}{0}$
which is the slope-intercept form
with slope $\left(\textcolor{g r e e n}{- 4}\right)$
and y-intercept $\textcolor{b l u e}{0}$

To determine the x-intercept, note that the x-intercept is the value of $x$ when $y = 0$
$\textcolor{w h i t e}{\text{XXX}} y = - 4 x$ evaluated with $y = 0$
$\textcolor{w h i t e}{\text{XXX}}$implies $x = 0$