This topic was pretty hard for me to understand, but after researching and practicing, it became more easy for me. Once you know the equation of a line on a graph, you can find the slope, plug in other numbers to see if it will affect anything, or you can try an other equation. The first think you need to know before doing anything else is knowing the formula: y=mx+b. That equation will help you determine a line on a graph. Once you know that, you can find the slope. In order to find the slope, first thing you need to find is the y- intercept. That is pretty easy to spot because it is when the line passes through the y-axis. Then when you find that, you just simply start from there and search for other points that passes through that line. I still have trouble with these problems because it can get confusing with all the numbers and stuff you have to do.
Can you possibly figure out if the slope on the equation of the line is correct? That isn't really difficult to do at all. The first thing you would have to do is look at the slope that is given to you in the equation. If that slope is on the line, then that should be correct.