Question 15485
x+y=4
2x-y=2 
First lets solve by substitution;
We will take the first equation and solve for x;
x+y=4
x=4-y
Now we substitute x=4-y in the other eqn for x;
2(4-y)-y=2; and we solve for y;
8-2y-y=2
8-3y=2
-3y=-6
-y=-2
y=2
Now we will solve for x using elimination;
We add eqn.1 and eqn. 2 together;
 x+y=4
2x-y=2
-------
3x=6
x=2
Now we have x=2, y=2, so we can check it by substituting it in eqn.1;
2+2=4
Hope you understand
=)