rearranging the equation gives us y=15-3x
if we were to find an equation for a PARALLEL line, we would just use the same slope.
if we were to find an equation for a PERPENDICULAR line, we would do the opposite reciprocal. in this case, that would be answer D. but this is WRONG!
the question asks us to find the slope of a PARALLEL line. thus, the answer is C.
final answer -- C.
