f(x) = 6x+3 g(x) = x2-5 tentukan a. (g0f)(4) b. (f0g) (-3)

a.(gof)(4)=(g(6.4 +3)=g(27)=27^2 - 5=  27.27 - 5 = 729 - 5 = 724
b.(fog)(-3) = f(g(-3)) = f(-3^2 -5) = f((-3)(-3) - 5) = f(9 - 5) = f(4) = 6.4 -3 = 24 - 3 = 21