Question

{x+y=12
{X=Y=2

{x+y=5
{x+3y=11

Answer 1

1)x=12-y

12-y-y=2

-2y=2-12

-2y=-10

y=-10/-2

y=5

2)x=5-y

5-y+3y=11

5+2y=11

2y=11-5

2y=6

y=6/2

y=3