# How do you find a standard form equation for the line with (-1, 9) and is perpendicular to the line whose equation is x = 8?

May 21, 2016

I found $y - 9 = 0$

#### Explanation:

Your equation $x = 8$ represents a perfectly VERTICAL line passing through $x = 8$ so a perpendicular to this one will be any HORIZONTAL line passing through $y = 9$ (from the condition of having $\left(- 1 , 9\right)$).
A horizontal line passing through $\left({x}_{0} = - 1 , {y}_{0} = 9\right)$ has zero slope, $m = 0$, and so we can write the general equation:
$y - {y}_{0} = m \left(x - {x}_{0}\right)$
$y - 9 = 0 \left(x + 1\right)$
or
$y - 9 = 0$