Question

Tìm x biết

2x/5-x/4=5/6

Giúp mình nha mai nộp rồi

Answer 1

Ta có: \(\dfrac{2x}{5}-\dfrac{x}{4}=\dfrac{5}{6}\)

\(\Leftrightarrow\dfrac{2x.12}{5.12}-\dfrac{x.15}{4.15}=\dfrac{5.10}{6.10}\)

\(\Leftrightarrow\dfrac{24x}{60}-\dfrac{15x}{60}=\dfrac{50}{60}\)

\(\Leftrightarrow\dfrac{24x-15x}{60}=\dfrac{50}{60}\)

\(\Leftrightarrow\dfrac{9x}{60}=\dfrac{50}{60}\)

\(\Leftrightarrow9x=50\)

\(\Leftrightarrow x=\dfrac{50}{9}\)

Answer 2

\(\dfrac{2x}{5}-\dfrac{x}{4}=\dfrac{5}{6}\)

\(\dfrac{8x}{20}-\dfrac{5x}{20}=\dfrac{5}{6}\)

\(\dfrac{8x-5x}{20}=\dfrac{5}{6}\)

\(\dfrac{3x}{20}=\dfrac{5}{6}\)

\(\dfrac{9x}{60}=\dfrac{50}{60}\)

\(\Rightarrow9x=50\)

\(\Rightarrow x=\dfrac{50}{9}\)