Graph the linear equation. Find three points to solve the equation, then plot on the graph.
-x-y=0

To graph, turn -x - y = 0 to y = -x by adding x to both sides then multiplying -1 to both sides. Then get points (0,0), (1, -1), and (2, -2) by replacing x with 0, 1, and 2 respectively and solving for y. Plot all of the points, and draw a line through them to graph.
Multiply both sides of -x-y=0 by -1 to obtain x + y = 0, and then solve for y:
y = -x This is a straight line whose graph is much like that of y = x, except that y decreases as x increases.
We may choose any desired x values and calculate the associated y-values.
x y = -x (x,y)
0 0 (0,0)
-2 2 (-2, 2)
4 -4 (4, -4)
Plot these three points on graph paper and then draw a straight line through them all.