Respuesta :

  x + y = 19
 -x + y = 1
      2y = 20
       2      2
        y = 10
  x + y = 19
x + 10 = 19
    - 10  - 10
         x = 9
   (x, y) = (9, 10)
ok so elimination
add them togehter
x+y=19
-x+y=1 +
0x+2y=20

2y=20
divide both sides by 2

y=10
subsitute
x+y=19
x+10=19
subtrac 10
x=9

x=9
y=10
(x,y)
(9,10)