`~rai~`
\(1,5+x=\dfrac{2}{5}-3\\\Rightarrow \dfrac{3}{2}+x=\dfrac{2}{5}-\dfrac{15}{5}\\\Rightarrow \dfrac{3}{2}+x=-\dfrac{13}{5}\\\Rightarrow x=-\dfrac{13}{5}-\dfrac{3}{2}\\\Rightarrow x=-\dfrac{26}{10}-\dfrac{15}{10}\\\Rightarrow x=-\dfrac{41}{10}=-4\dfrac{1}{10}.\\\text{Vậy }x=-4\dfrac{1}{10}.\)