Question

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

Answer 1

y = 1/2x - 3/2

Explanation:

The easiest way to find the inverse is to switch x and y and solve for y.

y = 2x + 3

x = 2y + 3 (Switch)

x-3 = 2y (Subtract y from both sides)

x/2 - 3/2 = y (Divide both sides by 2)

Answer 2

The inverse is 1/2x -3/2

Explanation:

y = 2x+3

To find the inverse, exchange x and y

x = 2y+3

Solve for y

Subtract 3 from each side

x-3 = 2y+3-3

x-3 =2y

Divide each side by 2

x/2 -3/2 = 2y/2

1/2x -3/2 =y

The inverse is 1/2x -3/2