Solve the following system of equations with the substitution method:

`{(y, =, -5 x -5),(25 x + 5 y,=,-25):}`

Answer: ( , )

Enter your answers as integers or as reduced fractions in the form A/B. If there is no solution, type "DNE" in each blank. If there are an infinite number of solutions, specify their form in the blanks in terms of x.