# How do you write an equation for each line in point-slope form and slope-intercept form if slope=4, passing through (1,3)?

Apr 3, 2015

For $\left(x , y\right)$ on a straight line and a fixed point $\left(a , b\right)$ also on the line, the constant slope, $m$ is
$\frac{y - b}{x - a} = m$
(that is, the change in $y$ divided by the corresponding change in $x$)

For the given example, we have
$\frac{y - 3}{x - 1} = 4$

Simplified as
$y - 3 = 4 \left(x - 1\right)$
for point-slope form

and
$y = 4 x - 1$
for point-intercept form