slope equation help  TOPIC_SOLVED

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slope equation help

Postby will82abn on Wed Feb 25, 2009 12:56 am

problem y=-1/2(x+2)
in a problem like this one i understand it until the end. Through (5,-2) with slope -1/2. i know how to set it up, the part i am missing out on is the fraction at the end like y=-1/2x+1/2 how do you get the last part the 1/2, i know its easy but i am missing. Thanks so much anyone RCW :confused:
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Postby stapel_eliz on Wed Feb 25, 2009 1:31 am

will82abn wrote:problem y=-1/2(x+2)
in a problem like this one i understand it until the end. Through (5,-2) with slope -1/2. i know how to set it up, the part i am missing out on is the fraction at the end like y=-1/2x+1/2 how do you get the last part the 1/2

How did you arrive at your answer? For instance, if you plugged the slope and the point into the point-slope formula so you had:

. . . . .y + 2 = -(1/2)(x - 5)

...by what steps did you arrive at "y = -(1/2)x + 1/2"?

Please be complete. Thank you! :D
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Postby stapel_eliz on Wed Feb 25, 2009 1:11 pm

In a private message, will82abn wrote:i am having problems with x1 not able or just don't see how to get the fraction at the end here is another problem y+3=3/4(x-2) then the problem begin when you dist the fraction 3/4 through to get 3/4x - 9/2 how to get the 9/2 is my prob.

Um... If I may venture to suggest, using standard capitalization, punctuation, and grammar might help explain your meaning (along with showing your steps)...?

I think you are saying (in the above quote) that you don't know how to work with fractions, so you don't understand how to multiply 3/4 and 2, and then to subtract 3, to end up with 9/2.

If you just need a little reminder of how to work with fractions, you could try studying this review. Otherwise, please take a break from what you're doing, and dedicate a few days or weeks to learning this topic. There are loads of great lessons available online, but the material can take a good while to absorb.

. . . . .Google results for "fractions"
. . . . .Google results for "simplifying fractions"
. . . . .Google results for "multiplying fractions"
. . . . .Google results for "dividing fractions"
. . . . .Google results for "least common multiple"
. . . . .Google results for "lowest common denominator"
. . . . .Google results for "adding fractions"
. . . . .Google results for "mixed numbers fractions convert"

:D
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Re:  TOPIC_SOLVED

Postby DAiv on Wed Feb 25, 2009 2:40 pm

will82abn wrote:i am having problems with x1 not able or just don't see how to get the fraction at the end here is another problem y+3=3/4(x-2) then the problem begin when you dist the fraction 3/4 through to get 3/4x - 9/2 how to get the 9/2 is my prob.

I find it easier to learn with examples to hand, so I'll lay it out, step by step, and hopefully, you may be able to see the pattern.



Distribute the through the parentheses:

, taking care with the minus sign.

Clean up:





To isolate the , so it's on its own, subtract 3 from both sides:



Clean up:



Now, in order to combine the with the , both numbers need to be in the form of a fraction with the same denominator (the number on the bottom). The simplest way to do that here is to convert the -3 into a fraction with a denominator of 2. We do that by multiplying it by ; this won't change the value, because any number divided by itself is 1, any number multiplied by 1 remains unchanged:



Clean up:



Now we can combine the two fractions:



If you can't see how

... you can rearrange the fractions like this:



We just need to be careful with the minus signs.

:D

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Re: slope equation help

Postby will82abn on Wed Feb 25, 2009 3:05 pm

Thanks DAvi, that was a great help, sorry if my standard capitalization, punctuation, and grammar was not up to par, first time user of this site. I knew it was somthing simple I was overlooking, but you nailed it thanks again. RCW :clap:
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