P varies directly as N and inversely as M P = \(\frac{\text{k N}}{\text{M}}\) 9 = \(\frac{ 8k}{12}\) 8k = 12 x 9 K = \(\frac{108}{8}\) = 13.5 P = \(\frac{13.5 N}{\text{M}}\) Find N, when M = 17, P = 27 27 = \(\frac{13.5 N}{17}\) 13.5 N = 27 x 17 = 459 N = \(\frac{459}{13.5\) = 34.