Answer:
y=-1/1x
Explanation:
First, let's take the slope of a line equation:
y=mx+b
Now, all we have to do is find the slope(m) and the y-intercept(b).
The line intercepts the y axis at 0, so b=0.
Next, find the slope.
The equation to FIND slope is rise/run, so we can solve that:
1/1=1, but since the line goes down, it's negative.
The slope is 1, so m=1.
Now, put that into m.
y=-1x+0, but we don't need 0, so the answer is y=-1x.