Try turning both lines into the slope intercept form, and then graph the two points. Where they intercept is the solution. This method is called "solving by graphing." You could also solve by elimination or substitution if you don't have a graph handy.
x+y=-3 ---This is the first equation. Subtract x from btoh sides to get it in the slope intercept form
y = -x -3
Now the first one is in the slope intercept form. Do the same thing to the second one.
x-y=-1 ---Subtract x from both side
-y = -x - 1 ---Now multiply everything by a negative. This will turn the negatives into positives.
y = x - 1
Now graph these lines. Here's what they look like graphed:
Here you can see that they intercept when x = -1, and when y = -2.
The solution is then x = -1 and y = -2.
