Respuesta :

x-2y=10                 x+3y=5
x=10+2y--(1)                x=5-3y--(2)

Equate (1) and (2) to find y,
10+2y=5-3y
3y+2y=5-10
5y=-5
y=-1

Substitute y=-1 into (1),
x=10+2(1)
  = 12