\(\left(\dfrac{2x}{5}+3\right):\left(-5\right)=\dfrac{-1}{25}\\ \dfrac{2x}{5}+3=\dfrac{-1}{25}\cdot\left(-5\right)\\ \dfrac{2x}{5}+3=\dfrac{1}{5}\\ \dfrac{2x+15}{5}=\dfrac{1}{5}\\ 2x+15=1\\ 2x=-14\\ x=-7\)
Vậy x = -7
\(\left(\dfrac{2x}{5}+3\right)\):\(\left(-5\right)=\dfrac{-1}{25}\)
\(\dfrac{2x}{5}+3=\dfrac{-1}{25}.\left(-5\right)\)
\(\dfrac{2x}{5}+3=\dfrac{1}{5}\)
\(\dfrac{2x}{5}=\dfrac{1}{5}+3\)
\(\dfrac{2x}{5}=\dfrac{16}{5}\)
2x=16
x=16:2
x=8
Vậy x= 8