Question

which of the following is the equation of a line perpendicular to the line y=(-3/2)x+4 passing through the point (3,9)?

A. -2x-3y=-21
B. 2x-3y=21
C. 2x+3y=21
D. -2x+3y=21

Answer 1

There are two ways of doing this:

1- with (normal) vectors
2- with slopes

Do either of these sound familiar to you?

Answer 2

I got it!