If the equation of the line is given in a form Ax + By + C = 0 then, the slope (m) is equal to -A / B. From the given equation of the line, A = 4 and B = 3. The slope of this line is -4/3. The line perpendicular to the given has a slope which is the negative reciprocal of the slope of the given. Hence, the slope of the perpendicular line is 3/4.
