x=3-3y x+3y=-6

need to find the graph points

First line:

x=3-3y

3y=3-x Divide with 3

y=1-x/3

y= -x/3 + 1

y=(-1/3)*x +1

Second line:

x+3y= -6

3y= -6-x Divide with 3

y= -2 -x/3

y= -x/3 - 2

y= (-1/3)*x -2

The equation of a straight line is usually written this way:

y = mx + b

m = Slope or Gradient (how steep the line is)

b = the Y Intercept (where the line crosses the Y axis)

In this case slope= -1/3 for both lines,so lines are parallel.

First line has y-Intercept 1

Second line has y-Intercept -2

Now in google type:
functions graphs online

When you see list of results clic on:
rechneronline.de/function-graphs/

When page be open in blue rectangle type:
-x/3 + 1

in gray rectangle type:
-x/3 - 2

and click option Draw