Answer:
(f*g)(x)=21x+8
Step-by-step explanation:
f(x)=7x
g(x)=3x+1
(f*g)(x)= 7(3x+1)+1
= 21x+7+1
=21x+8
Answer: The answer is 21x+7
(fog)(x)=f(3x+1)
f=7
7*3x=21x
7*1=7
Ans = 21x+7
