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Question 73773: Can you explain the step-by-step ways to solve a slope problem on graphing intercepts
Answer by ffc_01(9)   (Show Source):
You can put this solution on YOUR website! For a question about slope and intercepts you are probably given an equation in the form y=mx+b which is called slope intercept-form where m=slope and b= the y intercept. If you are given an equation in another form then change it into this form.
An example would be y = 3x + 2
Start with your y-intercept. In this case it is positive 2. The y intercept is the point (0,b). So for this problem it is (0,2). Graph this point. Keep in mind that the equation says y=mx+b so if you see a problem with y=mx-b your b is negative.
Then find your slope. Slope is the rise/run of the line. Since the slope is 3 and 3=3/1 starting at your y-int the line rises 3 and goes over 1 to the next point. Connect the points to form a line.
The slope in this case is positive so the rise should be in the positive y direction and the run is in the positive x direction. You can also go in the negative y and negative x directions because a negative over a negative is a positive. If slope is negative chose either the rise or the run to be negative and the other should be positive.
Important note about intercepts: The y intercept is the point where a line crosses the y axis and the x intercept is where the line crosses the x axis. The y axis is the line x=0 so to find the point where the line crosses x=0 plug 0 into the equation. If the equation is in the form y=mx+b then y=b when x is 0. So you get the point (0,b). To find the x intercept use the same concept. The x axis is the line y=0 so to find the point where your line crosses the x axis replace y in y=mx+b with 0. Now solve for x. 0=mx+b mx=-b x=-b/m. So when y=0, x=-b/m and you get the point (-b/m,0)
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