Given ${\displaystyle \underset{1}{\overset{4}{}}}f(x)dx=5,{\displaystyle \underset{4}{\overset{8}{}}}g(x)dx=6,{\displaystyle \underset{4}{\overset{8}{}}}h(x)dx=-8,$ and ${\displaystyle \underset{4}{\overset{1}{}}}f(x)dx={\displaystyle \underset{4}{\overset{8}{}}}\frac{6h(x)-g(x)}{2}dx={\displaystyle \underset{8}{\overset{1}{}}}r(x)dx=$