\(\dfrac{5}{4x}=\dfrac{3}{8}+\dfrac{5}{12}\Rightarrow\dfrac{5}{4x}=\dfrac{19}{24}\)\(\Leftrightarrow4x=\dfrac{5.24}{19}=\dfrac{120}{19}\)\(\Leftrightarrow x=\dfrac{\dfrac{120}{19}}{4}=\dfrac{30}{19}\)Câu trả lời: \(\dfrac{5}{4x}=\dfrac{3}{8}+\dfrac{5}{12}\Rightarrow\dfrac{5}{4x}=\dfrac{19}{24}\)\(\Leftrightarrow4x=\dfrac{5.24}{19}=\dfrac{120}{19}\)\(\Leftrightarrow x=\dfrac{\dfrac{120}{19}}{4}=\dfrac{30}{19}\)