$\text {2(x+$\frac{3}{5}$ = 5-($\frac{13}{5}$+x) }$
$\text {⇔2x+$\frac{6}{5}$ = 5-$\frac{13}{5}$-x }$
$\text {⇔2x+x = 5-$\frac{6}{5}$-$\frac{13}{5}$ }$
$\text {⇔3x = $\frac{25}{5}$-$\frac{6}{5}$-$\frac{13}{5}$ }$
$\text {⇔3x = $\frac{6}{5}$ }$
$\text {⇔x = $\frac{2}{5}$ }$
$\text {Vậy S={$\frac{2}{5}$} }$
$\text {Chúc bạn học tốt~}$