Answer:

Step-by-step explanation:
We want to find the inverse of the function:

To find the inverse of a function, we will flip the variables and solve for <em>y</em>. So:

Solve for <em>y</em>. Subtract two from both sides:

Divide both sides by two:

And take the principal square root of both sides. Therefore:

38.95 * 2 = 77.90.
115 - 77.90 = 37.10.
$37.10 is how much she can spend on the skirt.