Model their profits over 15 years

Describe the possible echelon forms of the standard matrix for a linear transformation t where t: set of real numbers is onto.

Which is the graph of the piecewise function f(x)? f(x)=[tex]f(x) = \left \{ {{-x+1, x\leq 0 } \atop {x+1, x\ \textgreater \ 0}} \right.[/tex]

Icould really use some with this question.