The given line has a slope of 1/5. Any new line perpendicular to this given line has a slope which is the negative reciprocal of 1/5: -5.
Use the point-slope equation of a line: y - k = m(x - h), where (h, k) is the point through which the new line passes. Here h = 15 and k = -4, so we have:
y + 4 = -5(x - 15)
This line is perpendicular to the given line and also passes through (15, -4).
