If f (x) = 4 - x2 and g (x) = 6x, which expression is equivalent to (g - f) (3) ?

F (x) = 4 - x² g (x) = 6x

(g - f) (x) = g (x) - f (x)

(g - f) (3) = g (3) - f (3)

g (x) = 6x

g (3) = 6*3 = 18

f (x) = 4 - x²

f (3) = 4 - 3² = 4 - 9 = - 5

(g - f) (3) = g (3) - f (3) = 18 - (-5) = 18 + 5 = 23

(g - f) (3) = 23