Question

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

Answer 1

Answer:

 -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

Answer 2

F(x)=
$f(x) = 2x + 3$
$let y = 2x + 3$
make y subject of the formula
$x = \frac{y - 3}{2}$
replace y with x above
$f ^{ - 1 } = \frac{x - 3}{2}$