# Help Find Slope :)

• Nov 14th 2007, 12:53 PM
Noelle
Help Find Slope :)
hey i know this is not the right page but whatever... i'm really horrible at math and i have a big test tomorrow :( i'll be posting up a lot of questions. i need to learn all of this in one night >_< is it possible to explain how to do each question with the answer? i have the list of multiple choice answers and the correct one as well, but i don't really remember how to do it. ty so much <3

Find the slope of the line that goes through each pair of points.

1) (1, -8) and (6, 5)
• Nov 14th 2007, 03:04 PM
Noelle
:(
• Nov 14th 2007, 03:42 PM
angel.white
Quote:

Originally Posted by Noelle
hey i know this is not the right page but whatever... i'm really horrible at math and i have a big test tomorrow :( i'll be posting up a lot of questions. i need to learn all of this in one night >_< is it possible to explain how to do each question with the answer? i have the list of multiple choice answers and the correct one as well, but i don't really remember how to do it. ty so much <3

Find the slope of the line that goes through each pair of points.

1) (1, -8) and (6, 5)

First of all, study ahead of time so that you 1. don't forget what you learned, and 2. aren't suddenly in a crunch such as this.
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For any given pair like that, the first number is the x value (how far to the right or left) and the second number is the y value (how far up and down) You can remember this, because x comes before y, so the first number is the x value.

Now, when finding the slope between these points, remember the phrase RISE OVER RUN. This means that you see how far up your new point is, then how far over, you see how far it rises (up or down) and then put that over how far it runs (left and right).

So for your equation, (1,-8) and (6,5) You can see that your rise is from -8 to 5, so your y value has risen 13 units. And your x value has gone from 1 to 6, so your x value run 5 units. So put 13 over 5, and that is your slope.

slope= $\displaystyle \frac{13}{5}$.

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The general formula for finding this is that you have 2 points $\displaystyle (x_1, y_1) \mbox{ and } (x_2,y_2)$ Don't get scared by the subscript numbers, it just means that the x is part of the first pair or the second pair (otherwise you wouldn't be able to tell them apart).

Slope is usually represented by the letter "m", and so people usually calculate m by $\displaystyle m=\frac{y_2-y_1}{x_2-x_1}$ Though I personally use $\displaystyle m=\frac{y_1-y_2}{x_1-x_2}$, it doesn't matter which, as long as you remember to start from the same pair.

In the end, the line has the same slope if you go from the second point to the first, or from the first to the second. So choose your point, circle it so you know you are starting from that point, then say RISE OVER RUN. And figure out the difference between the y values, and the difference between the x values by taking the starting y, and subtracting the finished y, then puting that over the starting x minus the finished x.
• Nov 14th 2007, 03:50 PM
angel.white
Here are some examples:

(1,5), (2,4) = $\displaystyle \frac{1-2}{5-4} = \frac{-1}{4}$

(3, 2), (-6,-7) = $\displaystyle \frac{3-(-6)}{2-(-7)}=\frac{3+6}{2+7}=\frac{9}{9}=1$

(-2,2), (4,-4) = $\displaystyle \frac{-2-4}{2-(-4)}=\frac{-6}{6}=-2$

(29,84), (11,-54) = $\displaystyle \frac{29-11}{84-(-54)}=\frac{18}{138}=\frac{3}{23}$

(a,b), (c,d) = $\displaystyle \frac{a-c}{b-d}$

Do you see the pattern?