# How do you write an equation of the line given (m = -3) and (b = 5)?

I'm assuming $b$ is the X-intercept for an equation of the form
$y = m \left(x - b\right)$
(and that the Y-intercept is $0$)
$y = - 3 \left(x - 5\right)$
$y = 15 - 3 x$