\(\dfrac{1}{3}\cdot x+\left(\dfrac{2}{3}-\dfrac{4}{9}\right)=-\dfrac{3}{4}\)
\(\dfrac{1}{3}x=-\dfrac{3}{4}-\left(\dfrac{2}{3}-\dfrac{4}{9}\right)\)
\(\dfrac{1}{3}x=-\dfrac{35}{36}\)
\(x=3\cdot\left(\dfrac{-35}{36}\right)\)
\(x=-\dfrac{35}{12}.\)
\(Vậy...\)
\(\left(\dfrac{5}{6}-\dfrac{3}{2}\right):\left(\dfrac{-2x}{3}\right)=-\dfrac{12}{19}\)
\(19=-x\cdot12\)
\(-x\cdot12=19\)
\(x=-\dfrac{19}{12}.\)
\(Vậy...\)
a,
\(\dfrac{1}{3}x+\dfrac{2.3-4}{9}=-\dfrac{3}{4}\\ \dfrac{1}{3}x+\dfrac{2}{9}=\dfrac{3}{4}\\ \dfrac{1}{3}x=\dfrac{3}{4}-\dfrac{2}{9}\\ \dfrac{1}{3}x=\dfrac{3.9-4.2}{36}\\ \dfrac{1}{3}x=\dfrac{19}{36}\\ x=\dfrac{19}{36}:\dfrac{1}{3}\\ x=\dfrac{19}{12}\)
b,\(\dfrac{5-3.3}{6}:\left(-\dfrac{2}{3}x\right)=-\dfrac{12}{19}\\ \dfrac{-2}{3}:-\dfrac{2}{3}x=-\dfrac{12}{19}\\ -\dfrac{2}{3}x=-\dfrac{12}{19}:\left(-\dfrac{2}{3}\right)\\ -\dfrac{2}{3}x=\dfrac{18}{19}\\ x=\dfrac{18}{19}:\left(-\dfrac{2}{3}\right)\\ x=-\dfrac{27}{19}\)