2.(x + \(\frac{3}{5}\)) = 5 - (\(\frac{13}{5}\) + x)
\(\Leftrightarrow\) 2x + \(\frac{6}{5}\) = 5 - \(\frac{13}{5}\) - x
\(\Leftrightarrow\) 2x + x = 5 - \(\frac{13}{5}\) - \(\frac{6}{5}\)
\(\Leftrightarrow\) 3x = \(\frac{6}{5}\)
\(\Leftrightarrow\) x = \(\frac{2}{5}\)
Vậy S = {\(\frac{2}{5}\)}
Chúc bn học tốt!!