QuestionConsider two functions $f$ and $g$ on $[3,7]$ such that $\int_{3}^{7} f(x) d x=13, \int_{3}^{7} g(x) d x=6, \int_{4}^{7} f(x) d x=5$, and $\int_{3}^{4} g(x) d x=4$. Evaluate the following integrals. a. $\int_{3}^{4} 2 f(x) d x=16$ (Simplify your answer.) b. $\int_{3}^{7}(f(x)-g(x)) d x=\square$ (Simplify your answer.)