\(\left(2\dfrac{4}{5}x-50\right):\dfrac{2}{3}=51\)
\(\left(\dfrac{14}{5}x-50\right):\dfrac{2}{3}=51\)
\(\left(\dfrac{14}{5}x-50\right)=51\cdot\dfrac{2}{3}\)
\(\dfrac{14}{5}x-50=34\)
\(\dfrac{14}{5}x=34+50\)
\(\dfrac{14}{5}x=84\)
\(x=84:\dfrac{14}{5}\)
\(x=30\)