You can put this solution on YOUR website! Solve by "substitution" means you will substitute one variable for one of the equations;
When you have two equatins,you solve one of them for x or y; then you use that answer to solve the other.
In this case you are already given what y =;
y=2x
Now substitute that into the 2nd equation to solve for x;
x+y=12
x+(2x)=12
3x=12
x=4
Now plug that into the equation to solve for y;
4+y=12
y=12-4
y=8
So your ordered pair would be;
(4,8)
hope you understand
=)
(