\(\dfrac{5}{6}+\dfrac{9}{10}.x=\dfrac{1}{6}\\ \Rightarrow\dfrac{9}{10}.x=\dfrac{1}{6}-\dfrac{5}{6}\\ \Rightarrow\dfrac{9}{10}.x=\dfrac{-2}{3}\\ \Rightarrow x=\dfrac{-2}{3}:\dfrac{9}{10}\\ \Rightarrow x=-\dfrac{20}{27}\)
9/10x=1/6-5/6
9/10x=-2/3
x=-2/3:9/10
x=-20/27