# If f(x) = 9x-4 and g(x) = 7x-9, what ix (f-g)(x)?

$\left(f - g\right) \left(x\right) = f \left(x\right) - g \left(x\right) = \left(9 x - 4\right) - \left(7 x - 9\right) = 9 x - 4 - 7 x + 9 = 2 x + 5$