Re: coordinate geometry: linear equations in two variables -- Mathematics Help

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Subject: Re: coordinate geometry: linear equations in two variables

Author:
Jamaine

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Date Posted: 00:43:22 10/27/11 Thu
In reply to: Misty Bowman 's message, "coordinate geometry: linear equations in two variables" on 18:06:25 06/18/05 Sat

>what is the equation of the line that contains the
>points with (x,y)coordinates(-3,7) and (5,-1)? I need
>to know how to do this problem step by step.

Well we start by knowing that the equation for finding the slope is m=(y1-y2)
-------
(x1-x2)

Just plug your coordinate's in :
you should get the answer -1

Then go back to slope form which is y=mx+b, insert one set of your coordinates along with your slope and solve for b.

for example 7=(-1)(-3) + b
7= 3 + b
-4=b
put this back in its form you have y=-x-4

hope this helps, and Im not a teacher so it might be explained a litte hood.

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[> [> Subject: Re: coordinate geometry: linear equations in two variables

Author:
geeknick (Mathy..!!!!)
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Date Posted: 23:21:52 12/15/11 Thu

Linear equations (slope) help?
I am just not getting this. If you could help me that would be wonderful! Thank you!

1. The pitch of a roof is just the slope of the roof. Of course in the real world, we don�t have an xyplane, so we only use positive (or at least non-negative) slopes.
(a) If a roof has a pitch of zero what does it look like?
(b) If the pitch of the roof is a very large number, what does the roof look like?
(c) Suppose your roof is 27 feet above the ground at its peak and only 22 feet above the ground at
the front of the house. How far does it rise?
(d) Suppose the front of the house is 17 feet from the street and the peak is 32 feet from the street
(measure just horizontally). How far is the run from the front edge to the peak?
(e) What is the pitch of this roof?
(f) Why do we care about the pitch of the roof? For what reasons could a steeper roof be better
and for what reasons would a less steep roof be better?
2. The grade of a road is just the slope converted into a percent. So when you find the slope, multiply
by 100 to get the grade. Again we use only non-negative slopes.
(a) A road rises 12 feet over a horizontal distance of 640 feet.
What is its slope?
What is its grade?
(b) A road has a 16.7% grade.
What is its slope?

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[> [> Subject: Re: coordinate geometry: linear equations in two variables

Author:
Davida
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Date Posted: 23:34:16 07/31/12 Tue

>>what is the equation of the line that contains the
>>points with (x,y)coordinates(-3,7) and (5,-1)? I need
>>to know how to do this problem step by step.
>
>
>Well we start by knowing that the equation for finding
>the slope is m=(y1-y2)
> -------
> (x1-x2)
>
>Just plug your coordinate's in :
>you should get the answer -1
>
>Then go back to slope form which is y=mx+b, insert one
>set of your coordinates along with your slope and
>solve for b.
>
>for example 7=(-1)(-3) + b
> 7= 3 + b
> 4=b
>put this back in its form you have y=-x+4
>
>hope this helps, and Im not a teacher so it might be
>explained a litte hood.

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