\(\dfrac{3}{7}-x=\dfrac{1}{4}-\left(-\dfrac{3}{5}\right)\)
\(\Rightarrow\dfrac{3}{7}-x=\dfrac{17}{20}\)
\(\Rightarrow x=\dfrac{-59}{140}\)
Vậy \(x=\dfrac{-59}{140}.\)
Lần sau tự làm mấy bài này đi bạn
\(\dfrac{3}{7}-x=\dfrac{1}{4}-\left(-\dfrac{3}{5}\right)\)
\(\dfrac{3}{7}-x=\) \(\dfrac{17}{20}\)
\(x=\dfrac{3}{7}-\dfrac{17}{20}\)
\(x=\dfrac{-59}{140}\)