How do you write an equation of the line perpendicular to the line x - 3y = 9 and passing through the point (3,5)?

1 Answer
Jul 4, 2015

Answer:

I found: #y=-3x+14#

Explanation:

Your perpendicular line musta have a slope #m_1# given as:
#m_1=-1/m# where #m# is the slope of your given line.
Your line can be written as:
#y=x/3-3#
The slope of your given line is equal to the numerical coefficient of #x#, i.e., #m=1/3#.
With this in mind the slope of the perpendicular will be: #m_1=-3#.
We can now use the general relatonship:
#y-y_0=m_1(x-x_0)# to find the equation of the perpendicuar line;
with your data:
#y-5=-3(x-3)#
#y=-3x+9+5#
#y=-3x+14#