Respuesta :

y = 9

7y - 10y = -3y
bring down the 9 = -18 so

-3y + 9 = -18

9 - 9 = 0
- 18 - 9 = - 27

- 3y ÷ - 3 = y
- 27 ÷ -3 = 9

therefore y =9