Use the two functions fx2x1 gx5x3 to evaluate the following

Use the two functions f(x)=2x+1 & g(x)=5x+3 to evaluate the following: (fog)(-1). Multiple choice: a. -15 b. 5 c. -5 d. 15 Please show work that shows why you chose your answer.

Solution

fog(x) = 2g(x) + 1 = 2(5x+3) + 1 = 10x+7

fog(-1) =10*-1+7 = -3

None of the answers mentioned is correct. Correct answer is -3.