What is the inverse of the function f(x) = 2x – 10?

Asap! i'm not good math and i'm lost.

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.