Move x to the right side, so we could get y=-3-x. If you didn't have a calculator, go to https://www.desmos.com/calculator and graph it. The rest is your work.
Y+x=-3 First, you move the x to the other side of the equals sign. so now it would be: y=-x-3. Now, you find one ordered pair. (0,-3). Now, you decrease the line by negative 1. I can't expain it that well. I hope that helps.