\(B=\left(\dfrac{-5}{3}+\dfrac{2}{5}\right):\dfrac{4}{5}+\left(\dfrac{-1}{3}+\dfrac{8}{5}\right):\dfrac{4}{5}\)
\(B=\dfrac{-5}{3}+\dfrac{2}{5}:\dfrac{4}{5}+\dfrac{-1}{3}+\dfrac{8}{5}:\dfrac{4}{5}\)
\(B=\left(\dfrac{-5}{3}+\dfrac{-1}{3}\right)+\left(\dfrac{2}{5}+\dfrac{8}{5}\right):\dfrac{4}{5}\)
\(B=\left[\left(-2\right)+2\right]:\dfrac{4}{5}\)
\(B=0:\dfrac{4}{5}=0\)
\(=>B=\dfrac{5}{4}\cdot\left(-\dfrac{5}{3}+\dfrac{2}{5}-\dfrac{1}{3}+\dfrac{8}{5}\right)=\dfrac{5}{4}\cdot\left(-2+2\right)=\dfrac{5}{4}\cdot0=0\)
\(=>C=\left(-\dfrac{2}{3}+\dfrac{1}{3}+\dfrac{1}{6}+\dfrac{1}{2}\right)+\left(\dfrac{1}{69}-\dfrac{1}{36}-\dfrac{2}{9}\right)\)
\(C=\left(-\dfrac{2}{6}+\dfrac{1}{6}+\dfrac{3}{6}\right)-\dfrac{65}{276}=\dfrac{1}{3}-\dfrac{65}{276}=\dfrac{157}{276}\)
\(C=\dfrac{1}{2}-\dfrac{2}{3}-\dfrac{-1}{3}+\dfrac{1}{69}-\dfrac{-2}{9}+\dfrac{1}{6}-\dfrac{1}{36}\)
\(C=\left(\dfrac{-2}{3}+\dfrac{1}{3}+\dfrac{1}{6}+\dfrac{1}{2}\right)-\left(\dfrac{1}{69}-\dfrac{1}{36}-\dfrac{2}{9}\right)\)
\(C=\dfrac{1}{3}-\dfrac{65}{276}\)
\(C=\dfrac{9}{92}\)
