Expert: Lynn Houston - 11/30/2010

Question
Find an equation for a line that is perpendicualr to 2x-3y+6=0 and has the same x intercept as 3x+7y+12=0

Answer
Start by putting the first eq into the slope intercept form

y = 2/3x + 2  

Perpendicular lines have negative inverse slopes, so the slope of the line you're looking for is -3/2.

Now take the other eq  3x + 7y + 12 = 0, to find the x intercept, set y = 0

3x + 0 = -12
x = -4 and since y = 0, you have a point of -4,0 to work with.  Take that information and fill it in to the y intercept form, with your known slope and solve for b

0 = -3/2(-4) + b
b = 12/2 = -6, so your final equation is y = -3/2x - 6