Question

Write the equation of a line that is perpendicular to the given line and that passes through the given point.

2x+9y=-30;(-8,0

Answer 1

2x+9y=-30 subtract 2x from both sides

9y=-2x-30 divide both sides by 9

y=-2x/9-30/9

So the slope of the reference line is -2/9. For a line to be perpendicular to this line their slopes must be negative reciprocals of one another, mathematically:

m1*m2=-1 and in this case:

-2m/9=-1

m=9/2

m=4.5, so far we have:

y=4.5x+b, using point (-8, 0) we can solve for b

0=4.5(-8)+b

0=-36+b

36=b, so our line is:

y=4.5x+36