Answer:
y-1=0
Explanation:
I'm going to write into y=mx+b form first.
m is the slope and b is the y-intercept.
First step is to find the slope.
To find the slope given two points you can use m=(y2-y1)/(x2-x1).
Instead, I like to line up the points and subtract vertically. Then put 2nd difference on top of 1st difference.
Let's do that:
(-2,1)
- (2,1)
--------
-4, 0
The slope is 0/-4=0. That means the line is horizontal and is of the form y=a number.
If you look at the points, you see the y-coordinate doesn't change. The y-coordinate is always 1. So the equation for the line is y=1.
If we subtract 1 on both sides we get y-1=0.
So general form is Ax+By+C=0 which is why I decide to move the one on the other side of the equation.
If I had noticed earlier that the y-coordinates were the same I would have stopped and say y=whatever y-coordinate I seen. However, I really didn't take notice of that until after I found the slope.