Question

1) x+2y=8
2)-x+34=17

Answer 1

Anis,
Supongo que se  trate  de resolver el sistema
De 2)
             34 - 17 =  x                                    x = 17
x en 1)
               17 + 2y = 8
                2y = 8 - 17
                2y = - 9
                                          y = - 9/2
                                       Solución                             
                                              x = 17
                                              y = - 9/2

Answer 2

34-17=x
x=17
Reemplazando:
17+2y=8
2y=-9
y=-9/2