Solve the following system of equations with the substitution method:

`{(-12 x + 3 y,=,-27),(y, =, 4 x -9):}`

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.