Question

What is the inverse of y = 3x + 9? A. y= 1/3x - 3 B. y = 1/3x + 9 C. y = -1/3x - 3 D. y = 9x + 3

Answer 1

1/3x - 3

Explanation:

To find the inverse, we exchange x and y and then solve for y

y =3x+9

Exchange x and y

x = 3y+9

Then solve for y

Subtract 9 from each side

x-9 =3y+9-9

x-9 = 3y

Divide by 3

1/3(x-9) = 3y/3

1/3(x-9) = y

Distribute

1/3x-3 = y

The inverse is 1/3 x -3