2x + 4y = - 4

x - 3y = - 12

1) 2x+4y=-4

2x=-4-4y

(x=-2-2y)

2 (-2-2y) + 4y=-4

-4-4y+4y=-4

[y=0]

2x+4 (0) = - 4

2x=-4

[x=-2]

check: 2 (-2) + 4 (0) = - 4, [-4=-4]

2) x-3y=-12

(x=-12+3y)

(-12+3y) - 3y=-12

[y=0]

x-3 (0) = - 12

[x=-12]

check:

(-12) - 3 (0) = - 12, [-12=-12]