Someone plz help me 20 points

Given the function f(x) = log base 4(x+8) , find the value of f^-1(2)

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.

Multiplying fractions by whole number 5 x 1/3=?