Both lines “r” and “s” pass through the point (k,9). Line “r” has a slope of −(4/3) and passes through the point (5,-3). Determine the:

(a) value of k.
(b) equation of “s” in standard form of ax + by + c = 0, if its x-intercept is -14.
(c) equation of line “t” perpendicular to line “r” which passes through the point (k,9) if form of y = mx + c.