Question

Need help asap please! If f(x)=7x and g(x)=3x+1 find (f o g)(x) A.10x+1 B.21x+1 C.21x^2+7x D.21x+7

Answer 1

Replace the x in 7x by (3x + 1):-

(f o g)(x) = 7 * (3x + 1)

= 21x + 7   which is choice D.

Answer 2

The choice for the answer is D