Answer
$-3J$
Work Step by Step
There are two triangles. Work done is basically area under the F vs x curve.
First triangle has (+) area, second triangle has (-) area.
First triangle area =W= $\frac{1}{2}\times2\times6=6J$
Second triangle area = W = $\frac{1}{2}\times3\times(-6)=-9J$
Total work done = $6-9=-3J$
