Question

Resolver:
A) x+3y=6
2x-y=-2

B) x+3y=4
2x-y=1

Answer 1

A)
x+3y=6
2x-y=-2

x=6-3y

2x-y=-2
2(6-3y)-y=-2
12-6y-y=-2
12-7y=-2
-7y=-2-12
-7y=-14
y=-14/-7
y=2

x=6-3y
x=6-3(2)
x=6-6
x=0

Comprobación
x+3y=6
0 + 3(2) = 6
6=6

2x-y=-2
2(0)-2=-2
0-2=-2
-2=-2

B)
x+3y=4
2x-y=1

x+3y=4
x=4-3y

2x-y=1
2(4-3y)-y=1
8-6y-y=1
8-7y=1
-7y=1-8
-7y=-7
y=-7/-7
y=1

x=4-3y
x=4-3(1)
x=4-3
x=1

Comprobación
x+3y=4
1 + 3(1)=4
1+3=4
4=4

2x-y=1
2(1)-1=1
2-1=1
1=1