Question

The formula s=0.04n+2500 gives an employees monthly salary s, in dollars, after selling n dollars in merchandise at an appliance store.

a) find the inverse of the function. is the inverse a function?

b) use the inverse to find the same amount of merchandise sold if the employees salary was $2820 last month.

Answer 1

a) Find the inverse of the function
s=0.04n+2500
s-2500=0.04n+2500-2500
s-2500=0.04n
s/0.04-2500/0.04=0.04n/0.04
25s-62,500=n
n=25s-62,500
Answer: The inverse of the function is n=25s-62,500

Is the inverse a function?
Yes, the inverse is a function, a linear function.

b) Use the inverse to find the same amount of merchandise sold if the employees salary was $2820 last month.
s=2,820→n=25(2,820)-62,500
n=70,500-62,500
n=8,000
Answer: The amount of merchandise sold was $8,000