Frank and Michelle are Kayaking to an island that's 9 miles downstream from there house. They have already traveled 1 mile, and they are rowing at a constant rate of 4 mi/h. A function f models their distance from home as a function of time. Write the function that models their distance from home as a function of time, then complete the statement below.

Function: f(x) = x +

f(1.5) = . The value indicates that after hours of rowing, Frank and Michelle will be miles from home.