Respuesta :

f(x)=3x+1 and g(x)=x^2-7

(f o g) (4) = f(g(4))

so
g(4) = 4
^2 - 7 = 16 - 7 = 9
f(g(4)) = 3(9)+1 = 27 + 1 = 28

answer
(f o g) (4) = 28