Which function is the inverse of f(x) =2x +3

 -1

f     (x) = x/2 - 3/2

Step-by-step explanation:

I choose to address this question by actually finding the inverse of f(x) = 2x + 3.

1) replace f(x) with y:  y = 2x + 3

2) interchange x and y:  x = 2y + 3

3) solve this result for y:  2y = x - 3 , or  y = (x - 3)/2.  This is the same as the second answer choice.  Label this result as

 -1

f     (x) = x/2 - 3/2

(f - g)(x) = 5x^3 - 3

step-by-step explanation:

rearrange these functions vertically, with like terms in separate columns:

f(x) = 5x^3 - 2

g(x) =         +1

now subtract, column by column:

(f - g)(x) = 5x^3 - 3