If you use the slope intercept form equation y=mx+b
m=slope
b=y intercept
since you already know the value of m you can put that in
y=-2x+b
So you just need a value for b
since we know that the slope is -2 we can write that as -2/1
use rise over run to find the y intercept
you would go down 2 points and to the right 1 point from (-2,7) and end up at (-1,5)
The next point would be (0,3) that point lines on the y axis so the y intercept is 3
so your equation would be y=-2x+3. Here is the graph of the line:
