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Subject: coordinate geometry: linear equations in two variables


Author:
Misty Bowman
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Date Posted: 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.

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


Author:
QUITTNER
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Date Posted: 07:17:31 06/20/05 Mon

>>> what is the equation of the line that contains the points with (x,y)coordinates(-3,7) and (5,-1)? <<<
..... The equation of a straight line is y=ax+b. Just insert the given values into the two simultaneous equations, and solve them for a and for b.
7=(-3)a + b
(-1)= 5a + b

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


Author:
kanishkporwal
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Date Posted: 00:44:59 09/15/11 Thu

>>>> what is the equation of the line that contains the
>points with (x,y)coordinates(-3,7) and (5,-1)? <<<
>..... The equation of a straight line is y=ax+b. Just
>insert the given values into the two simultaneous
>equations, and solve them for a and for b.
> 7=(-3)a + b
>(-1)= 5a + b
now you just need to solve these two linear equations
for solving linear equations you just need to
subtract eq 2 from eq 1 to get
8=(-8)a
a=-1
put a in any of the two equations to find b

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


Author:
fizixx
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Date Posted: 18:01:22 12/01/05 Thu

>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.

The equation of a line is:

y = mx + b

m is the slope
x is the independent variable
b is the 'y' intercept
y is the dependent variable

You essentially have to supply 'm' and 'b'.

You can use the following formula:

y - y1 = mx - x1

This is the pont-slope equation, and you have all this information at hand.

m = (y2 - y1)/(x2 - x1)

Let

y1 = -3
y2 = 5
x1 = 7
x2 = -1

It really doesn't matter which ones you pick, as long as the x values correspond to the actual x coordinate given....same for y.. in other words. If you have (8,5)....x = 8 and y = 5. You can't switch this. Understand?

So, plug this in and you will find that m = -8/8 = -1

Then the point-slope equation becomes:

y - 7 = -x - (-3)
==> y - 7 = -x + 3
==> y = -x + 3 + 7
==> y = -x + 10

That's your equation. Hope this makes sense.

fizixx

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


Author:
Yvette Jones
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Date Posted: 16:09:10 01/24/11 Mon

>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.

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


Author:
nicole heath
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Date Posted: 13:25:41 03/07/11 Mon

>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.

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


Author:
Amber
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Date Posted: 16:45:05 04/27/11 Wed

>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.
THE ABOVE ANSWER IS INCORRECT!!! The answer is y=-X+4
PLEASE EXPLAIN HOW!!!! THANKS!

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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

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


Author:
erica
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Date Posted: 15:18:37 11/01/11 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.

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


Author:
NICK (http://calculator.tutorvista.com)
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Date Posted: 00:22:07 11/03/11 Thu

Steps for Calculating Compound Interest
Step 1 :

Formula for calculating the total amount,

Total amount = P(1+(R/100))n.

Compound interest = Total amount - principal.


Step 2 :

When the Time is given in months then:

1 month= 0.08, 2 months = 0.17, 3 months= 0.25, 4 months= 0.33, 5 months= 0.42, 6 months= 0.50, 7 months= 0.58, 8 months= 0.67, 9 months= 0.75, 10 months= 0.83 and 11 months= 0.92.

http://calculator.tutorvista.com/math/33/compound-interest-calculator.html

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


Author:
Engr. Lawrence peter
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Date Posted: 09:38:03 09/08/12 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.
solution
lets assume that (-3,7) is coordinate 1 i.e x1 is -3 y1 is 7 and (5,-1) is coordinate 2 i.e x2 is 5 and y2 is -1
using d formula
y-y1/x-x1=y2-y1/x2-x1
by putting in the values of the coordinate u get
y-7/x-(-3)= -1-7/5-(-3)
y-7/x+3 =-8/5+3
y-7/x+3= -8/8
y-7/x+3=-1/1
by cross multiplying you get
1(y-7)=-1(x+3)
open the brackets you get
y-7=-x-3
collect like terms you get
y+x=7-3
y+x=4
this is your required equatn thank you hope I helped

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


Author:
MK (Thankful)
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Date Posted: 13:49:40 08/19/15 Wed

>>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.
> solution
>lets assume that (-3,7) is coordinate 1 i.e x1 is -3
>y1 is 7 and (5,-1) is coordinate 2 i.e x2 is 5 and y2
>is -1
>using d formula
> y-y1/x-x1=y2-y1/x2-x1
>by putting in the values of the coordinate u get
>y-7/x-(-3)= -1-7/5-(-3)
>y-7/x+3 =-8/5+3
>y-7/x+3= -8/8
>y-7/x+3=-1/1
>by cross multiplying you get
>1(y-7)=-1(x+3)
>open the brackets you get
>y-7=-x-3
>collect like terms you get
>y+x=7-3
>y+x=4
>this is your required equatn thank you hope I helped



It definitely helped, sir. THANKS ALOT!

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


Author:
kimberley
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Date Posted: 14:17:45 02/09/13 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.esaiser version

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