In order for a line to be perpendicular, it's slope must be the negative reciprocal -- meaning you turn the fraction upside down and positive slopes turn to negatives whilst negative slopes turn to positive. The perpendicular slope of the slope -4 is 1/4. Now use the point slope formula to insert the point (3,-3) to find the y-intercept (b). The answer is
[tex]y = \frac{1}{4}x - \frac{15}{4} [/tex]
