Question 558278
{{{-x-2y=6}}}is a linear equation. (You could call it a linear function too. Given a value for x, you can calculate the one value for y corresponding to that value of x).
Its graph is a straight line.
All you need to do is plot 2 points and connect them with a straight line.
You want to chose two points that are easy to calculate and make graphing easy.
In this case, I would pick {{{x=0}}} for one point and {{{y=0}}} for the other.
For {{{x=0}}}, {{{-2y=6}}} --> {{{y=-3}}}, giving you the point (0,-3).
For {{{y=0}}}, {{{-x=6}}} --> {{{x=-6}}}, giving you the point (-6,0).
Those points are easy to calculate, easy to plot, and reasonably spaced to allow you to draw a good line.
Then you just have to draw your x-axis and y-axis so that your points appear sort of in the middle of the graph.
{{{drawing(300,240, -8,2,-5,3,
grid(1),
red(circle(-6,0,0.2)),
red(circle(0,-3,0.2)),
blue(line(-8,1,4,-5))
)}}}