Question

alguém sabe ??

x+y= 48
2x-y=12

Answer 1

x+y=48 -> x=48-y
2x-y=12

2x-y=12
2(48-y)-y=12
96-2y-y=12
-2y-y=12-96
-3y=-84
y=-84/-3
y=28

x+y=48
x+28=48
x=48-28
x=20