1. How do I find slope? What does a positive or negative slope mean?

If your looking at a graph, you find the slope by going to a random point, and using rise/run to go to the next point. A negative slope means the function is decreasing, and a positive slope means the function is increasing.

other answer is correct. i had used the radius of the radius somehow. a website:

y=3x+4

step-by-step explanation:

given the points a(0,4) and b(-4, -8)

eqn of line ab: (y-4)/(x-0)=(-8-4)/(-4-0)

(y-4)/x=-12/-4=3

y=3x+4