\(\left(\dfrac{3}{8}-\dfrac{1}{5}\right)+\left(\dfrac{5}{8}-x\right)=\dfrac{1}{5}\)
\(\Leftrightarrow\dfrac{4}{5}-x=\dfrac{1}{5}\)
hay \(x=\dfrac{3}{5}\)
f)\(\left(\dfrac{3}{8}-\dfrac{1}{5}\right)+\left(\dfrac{5}{8}-x\right)=\dfrac{1}{5}\Leftrightarrow1-\dfrac{1}{5}-x=\dfrac{1}{5}\Leftrightarrow x=1-\dfrac{1}{5}-\dfrac{1}{5}=\dfrac{3}{5}\)
7/40+(5/8-x)=1/5
5/8-x=-1/40
x=13/20
\(\left(\dfrac{3}{8}-\dfrac{1}{5}\right)+\left(\dfrac{5}{8}-x\right)=\dfrac{1}{5}\)
<=> \(\dfrac{7}{40}+\dfrac{5}{8}-x=\dfrac{1}{5}\)
<=> x = \(\dfrac{7}{40}+\dfrac{5}{8}-\dfrac{1}{5}\)
<=> x = \(\dfrac{3}{5}\)