How do you write an equation of a line given (12,3) and perpendicular to 3x-y=2?
take your equation
...with slope m = 3.
The slope of the line you are trying to find is the negative inverse of this, since we're told that it's perpendicular. This slope is therefore
You can then solve for the offset in the equation:
...you solve for b by plugging in the x value (12) that you are given on the right side, and the y value (3) that you are given on the left:
so your equation is