Express the function f(x) = 5|x-1|-|x+1| in piecewise form without using absolute values. [Suggestion: It may help to generate the graph of the function.] f(x)=\left\{\begin{array}{ll}

f_{1} & x \leq a \\

f_{2} & a

f_{3} & x \geq b

\end{array}\right.