What is the solution to the system of equations

x - 2y  = 19     ⇒  x   =  19 + 2y      (1)

x + 3y  = 14    (2)

Sub (1) into (2)  for x  and we have

[ 19 + 2y ]  + 3y  = 14

19 + 5y  = 14    subtract 19 from both sides

5y = - 5    divide both sides by 5

y = - 1

And using (1) we have that

x = 19 + 2(-1)  =  19 - 2  =  17

So

(x, y)   =  ( 17, - 1)