A cell phone plan uses a fixed charge of $20 per month plus 10 cents for each minute used to calculate the total bill. The total bill, t, can be expressed in terms of the number of minutes, m, by the function rule t=20+0.10m. Which rule describes the inverse function?
We have function t=20+0.10m and we want to find inverse function, so we want to have value of m in times of t. t=20+0.10m /-20 both sides t-20=0.10m /*10 (multiply both sides by 10) 10t-200=m m=10t-200 - its the final result, so the answer is D.
