How do you find the slope of an equation

To find the slope you use a formula like y=mx+b y would be the point of whatever point is on the y axis so for example lets say 6 is your y axis and 8 is your a axis point once you have those point then you graph them. after they have been graphed you find the next point that would go in the sequence which would be at -8,-6 draw a line connecting the two point and then on every corner that the line completely goes through those are your other points then from there you take your original point and the next point closets to the original one and count down and to the left or right how ever many times you need to until you reach the nearest point. if you cant figure it out them this well help www.desmos.com/calculator

The answer is 8 apex