Ta có: \(\dfrac{2x}{5}-\dfrac{x}{4}=\dfrac{5}{6}\)
\(\Leftrightarrow\dfrac{2x.12}{5.12}-\dfrac{x.15}{4.15}=\dfrac{5.10}{6.10}\)
\(\Leftrightarrow\dfrac{24x}{60}-\dfrac{15x}{60}=\dfrac{50}{60}\)
\(\Leftrightarrow\dfrac{24x-15x}{60}=\dfrac{50}{60}\)
\(\Leftrightarrow\dfrac{9x}{60}=\dfrac{50}{60}\)
\(\Leftrightarrow9x=50\)
\(\Leftrightarrow x=\dfrac{50}{9}\)
\(\dfrac{2x}{5}-\dfrac{x}{4}=\dfrac{5}{6}\)
\(\dfrac{8x}{20}-\dfrac{5x}{20}=\dfrac{5}{6}\)
\(\dfrac{8x-5x}{20}=\dfrac{5}{6}\)
\(\dfrac{3x}{20}=\dfrac{5}{6}\)
\(\dfrac{9x}{60}=\dfrac{50}{60}\)
\(\Rightarrow9x=50\)
\(\Rightarrow x=\dfrac{50}{9}\)
