Question

1~ resolva

x + 5y = 60
x + y = 60

2) resolva

2× + 10y = 120
2x - 2y = 40

Answer 1

x + 5y = 60 
x + y = 60    ( - 1)

  x + 5y = 60
- x - y = - 60   (+)
        4y = 0
y = 0/4
y = 0

x + 5y = 60
x + 5.0 = 60
x + 0 = 60
x = 60 

x = 60
------------------------------------
2x + 10y = 120    
2x - 2y = 40       ( - 1)

  2x + 10y = 120
- 2x + 2y = - 40    (+)
        12y = 80

y = 80  (:4)  = 20
      12  (:4)      3

y = 20
       3

2x + 10y = 120
2x + 10.20 = 120
             3

2x + 200 = 120
          3

mmc =3

6x + 200 = 360
      3           3

6x = 360 - 200
6x = 160

x = 160 (:2)  =  80
        6  (:2)       3

x = 80
       3