SOLUTION: How do you calculate slopes in Algebra?

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Question 18587: How do you calculate slopes in Algebra?
Answer by Alwayscheerful(414) About Me  (Show Source):
You can put this solution on YOUR website!
There are 3 ways to do this problem.
1st and 2nd
It really isn't a second way, it's just a formula rearranged.
Given two points (x[1], y[1]) and (x[2], y[2]), the formula for the slope on the straight line going through these two points is:
m=%28y%5B1%5D-y%5B2%5D%29%2F%28x%5B1%5D-x%5B2%5D%29
Your math book may say
m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 but they both eventually equal the same thing.
EXAMPLE 1
(0,-4) and (3,-2)
I'll do it both ways to show you.
m=%28-4-%28-2%29%29%2F%280-3%29
m=-2%2F-3which equalsm=2%2F3
the other way:
m=%28-2-%28-4%29%29%2F%283-0%29
m=2%2F3

METHOD 2
You can find the slope by graphing if they give you two points.
For example, (0,-4) and (3,-2)
The graph should the look like this:
graph%28300%2C200%2C-5%2C5%2C-5%2C5%2C%282%2F3%29x-4%29
If you did this on graph paper, you can see that it intersects every so often. Then you just count the number of squares it goes up, then you count across and put the first number over the second number, and you get your slope!
Hope this helps!