Answer:
y=-6
Explanation:
y=mx+b, b is the y-intercept, m is slope
slope (m)= rise/run
(-6--6)/(7-3)=
0/4=
0
So plug it in.
y=(0)x+b
y=b
But what is y?
Pick either coordinate and plug the y-value into the equation y=b.
Now you have -6=b
So the final equation is y=-6.
It doesn't matter what the x value is, it's going to be multiplied by 0, the y coordinate on this line will always be -6.
Alternatively, you can plot it out, both (7,-6) and (3,-6) have the same y coordinate, therefore you can immediately see that the slope=0 because it's just a horizontal line.