Question

Tìm x :

\(\dfrac{2}{3x}-\dfrac{3}{12}=\dfrac{4}{5}-(\dfrac{7}{x}-2)\)

Answer 1

\(\dfrac{2}{3x}\)-\(\dfrac{3}{12}\)= \(\dfrac{4}{5}\)-\(\left(\dfrac{7}{x}-2\right)\)
\(\dfrac{2}{3x}-\dfrac{1}{4}=\dfrac{4}{5}-\dfrac{7}{x}+2\)
\(\dfrac{2}{3x}+\dfrac{7}{x}=\dfrac{4}{5}+\dfrac{1}{4}+2\)
\(\dfrac{2x}{3x^2}+\dfrac{21x}{3x^2}=\dfrac{61}{20}\)
\(\dfrac{2x+21x}{3x^2}=\dfrac{61}{20}\)
=> 20(2x + 21x)= 61.3x\(^2\)
=> 40x + 420x= 183x\(^2\)
=>460x = 183x\(^2\)
=> \(\dfrac{460}{183}\)= \(\dfrac{x^2}{x}\)
=> x=\(\dfrac{460}{183}\)