How do write the point-slope form of an equation for a horizontal line that passes through (5,-9)?

1 Answer
Aug 10, 2016

#y = 0x -9#, or just #y = -9#

Explanation:

The line is horizontal, therefore its slope is equal to 0.

All horizontal lines are written as # y = ....#

In #y = mx +c#, if the slope is 0, then there is no #x#-term and we have # y = c#

The y-value of the point that was given is the same as the y-intercept, because for any x-value, the y-value will always be the same. So #y = -9#

The equation of the line is

#y = 0x -9#