Solve the Problem $f(x)=m x+b$ Is a Mathematical Model for Actual Time as a Function

Solve the problem.
-Suppose $f(x) =m x+b$ is a mathematical model for actual time as a function of estimated time, where $f(x)$ represents actual time (in minutes) , $x$ represents estimated time (in minutes) , and $m$ and $\mathrm{b}$ are constants. If $\mathrm{m}=2$ and $\mathrm{b}=-2.6$ , find $f(x)$ when $\mathrm{x}$ is 120 minutes.

A) $242.6 \mathrm{~min}$
B) $125.2 \mathrm{~min}$
C) $114.8 \mathrm{~min}$
D) $237.4 \mathrm{~min}$