Question

Resolva o sistema:
X-y=1
X-3y=-3

Answer 1

x=1+y

1+y-3y=-3
-2y=-3-1
-2y=-4
y=-4/-2
y=2

x=1+2
x=3

espero ajudar ♥

Answer 2

X-y=1
X-3y=-3

x = 1 + y

x - 3y = -3 
1 + y - 3y = -3 - 1 
y - 3y = -4
-2y = -4 . (-1)
2y = 4
y = 4/2 
y = 2 

x = 1 + y 
x = 1 + 2
x = 3