17: \(\dfrac{5}{3}\left(-\dfrac{6}{5}+x\right)-\dfrac{1}{4}\left(\dfrac{2}{3}-1\right)=-\dfrac{3}{8}\)
=>\(-\dfrac{6}{3}+\dfrac{5}{3}x-\dfrac{2}{12}+\dfrac{1}{4}=-\dfrac{3}{8}\)
=>\(\dfrac{5}{3}x=-\dfrac{3}{8}-\dfrac{1}{4}+\dfrac{1}{6}+\dfrac{6}{3}\)
=>\(\dfrac{5}{3}x=-\dfrac{5}{8}+\dfrac{1}{6}+2=\dfrac{37}{24}\)
=>\(x=\dfrac{37}{24}:\dfrac{5}{3}=\dfrac{37}{24}\cdot\dfrac{3}{5}=\dfrac{37}{40}\)
18: \(-\dfrac{3}{4}\left(\dfrac{8}{9}-x\right)+\dfrac{3}{5}=-\dfrac{2}{3}\cdot\dfrac{1}{2}\)
=>\(-\dfrac{3}{4}\left(\dfrac{8}{9}-x\right)=-\dfrac{1}{3}-\dfrac{3}{5}=\dfrac{-14}{15}\)
=>\(\dfrac{8}{9}-x=\dfrac{-14}{15}:\dfrac{-3}{4}=\dfrac{14}{15}\cdot\dfrac{4}{3}=\dfrac{56}{45}\)
=>\(x=\dfrac{8}{9}-\dfrac{56}{45}=\dfrac{40}{45}-\dfrac{56}{45}=-\dfrac{16}{45}\)
19: \(\dfrac{2}{3}\left(x-\dfrac{9}{4}\right)=\dfrac{3}{7}\left(7-\dfrac{1}{6}\right)-\dfrac{1}{3}\)
=>\(\dfrac{2}{3}\left(x-\dfrac{9}{4}\right)=3-\dfrac{1}{14}-\dfrac{1}{3}=\dfrac{109}{42}\)
=>\(x-\dfrac{9}{4}=\dfrac{109}{42}:\dfrac{2}{3}=\dfrac{109}{28}\)
=>\(x=\dfrac{109}{28}+\dfrac{9}{4}=\dfrac{43}{7}\)
20: \(4-\dfrac{2}{3}\left(x-3\right)=2-\dfrac{1}{2}+\dfrac{2}{3}\)
=>\(4-\dfrac{2}{3}\left(x-3\right)=\dfrac{13}{6}\)
=>\(\dfrac{2}{3}\left(x-3\right)=4-\dfrac{13}{6}=\dfrac{11}{6}\)
=>\(x-3=\dfrac{11}{6}:\dfrac{2}{3}=\dfrac{11}{6}\cdot\dfrac{3}{2}=\dfrac{33}{12}=\dfrac{11}{4}\)
=>\(x=\dfrac{11}{4}+3=\dfrac{23}{4}\)
