Simply graph and on one graph like this
graph of (red) and (green)
The solution to the system is the point of intersection. So it appears they intersect at (1,2). So the solution is (1,2).
If you aren't allowed to use a graphing calculator, then you must make a table for each equation.
So if you let x=1 you get
and you would do this for every point in your table
So the table for would look like
x y
-5.00000 8.00000
-4.00000 7.00000
-3.00000 6.00000
-2.00000 5.00000
-1.00000 4.00000
0.00000 3.00000
1.00000 2.00000
2.00000 1.00000
3.00000 0.00000
4.00000 -1.00000
5.00000 -2.00000
Also, if you're required to make tables, you would have to make another table for
After making the tables, you can simply plot them on graphing paper to see where they intersect. That intersection is the solution.