Graphs of piecewise linear functions

Draw the graph of a piecewise function or determine its formula from its graph.

Problem

f is a continuous piecewise linear function defined as follows:
f(x)={x4,[10,4)0.2x+0.8,[4,1)1.125x+2.125,[1,9)15x143,[9,10]\qquad f(x) = \begin{cases} -x-4 & , & [-10,-4) \\\\ 0.2x+0.8 & , & [-4,1)\\\\ -1.125x+2.125 & , & [1,9)\\\\ 15x-143 & , & [9,10]\end{cases}
Drag the ends of the segments below to graph f.