Chapter 5, Problem 18RE

To determine

To evaluate: The value of integral $-{\displaystyle \underset{4}{\overset{1}{\int }}2f\left(x\right)dx}$ by using the facts ${\displaystyle \underset{1}{\overset{4}{\int }}f\left(x\right)dx}=6$, ${\displaystyle \underset{1}{\overset{4}{\int }}g\left(x\right)dx}=4$ and ${\displaystyle \underset{3}{\overset{4}{\int }}f\left(x\right)dx}=2$ or whether there is not enough information.