Question

The function f(x) = 1.50x – 30 gives the amount of money Amelia has to spend each week for x school lunches, after taking money out for savings. What is the inverse function?

Answer 1

To find the inverse, switch the x and y, and then solve for y (f(x) is the same as y)

So we get:
x=1.50y-30 (add 30 to both sides)
x+30=1.50y (divide both sides by 1.5)
x/1.5+30/1.5=y
y=x/1.5+20

Hope this helps