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

Answer 1

Their slopes must negative reciprocals of each other. So the new equation must be
3x - y = c

but (9,-5) lies on it, so
3(9) - (-5) = c
c = 32
and your equation is
3x - y = 32