Respuesta :

well,  (f o g)(4) is just another way of saying f(   g(4)   ).

so, we can simply first find g(4), and then plug that in f(x),

[tex]\bf \begin{cases} f(x)&=3x+1\\ g(x)&=x^2-6\\ (f\circ g)(4)&=f(~~g(4)~~) \end{cases} \\\\\\ g(4)=(4)^2-6\implies g(4)=16-6\implies g(4)=10 \\\\\\ f(~~g(4)~~)\implies f(~~10~~)=3(10)+1\implies f(~~10~~)=31[/tex]