Question 235894
x = -2y

This is a linear function.

All you need is two points to graph it.

Linear functions make straight lines.  The word linear means line.

There are many ways to find points.  

Let x = 0

0 = -2y

0/-2 = y

0 = y

One point to graph is (0,0).  This particular point is called the origin.
It's where the x and y axis meet.

Solving for y, we get the equation y = x/-2.

If we let x = 2, y = -1.

This makes the point (0, -1).

Plot these two points on the xy-plane and connect the points with a straight line going from quadrant 2 down through the origin into quadrant 4.