SOLUTION: Find the equation, in standard form, with all integer coefficients, of the line perpendicular to x + 3y = 12 and passing through (9, -5).

Algebra ->  Equations -> SOLUTION: Find the equation, in standard form, with all integer coefficients, of the line perpendicular to x + 3y = 12 and passing through (9, -5).      Log On


   

Question 145481: Find the equation, in standard form, with all integer coefficients, of the line perpendicular to x + 3y = 12 and passing through (9, -5).
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
First get the equation in the form
y+=+mx+%2B+b
where m is the slope, then the line perpendicular
to it will have slope = m%5B1%5D+=+-%281%2Fm%29
x+%2B+3y+=+12
subtract x from both sides
3y+=+-x+%2B+12
divide both sides by 3
y+=+-%281%2F3%29x+%2B+4
m%5B1%5D+=+-%281%2Fm%29
m%5B1%5D+=+-%281%2F%28-1%2F3%29%29
m%5B1%5D+=+3
So the line perpendicular to the given line will look like
y+=+3x+%2B+b
To find b, plug (9, -5) into the equation
-5+=+3%2A9+%2B+b
-5+-+27+=+b
b+=+-32
The answer is y+=+3x+-+32
check:
does it go through (9, -5)?
-5+=+3%2A9+-+32
-5+=+27+-+32
-5+=+-5
OK