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Math Help - not sure if it is algebra...

  1. #1
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    not sure if it is algebra...

    but im not sure how i would solve this (question in attachment!)
    could someone please point me in the right direction to solving this question!?!

    not sure if it is algebra...-1.jpg

    Thanks!!
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  2. #2
    Senior Member yeKciM's Avatar
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    Quote Originally Posted by andyboy179 View Post
    but im not sure how i would solve this (question in attachment!)
    could someone please point me in the right direction to solving this question!?!

    Click image for larger version. 

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    Thanks!!
    \displaystyle \frac {2x+1} {3x-7}= 2

    multiply all with 3x-7

     2x+1= 2\cdot (3x-7)

     2x+1 = 6x-14

     4x = 15 \Rightarrow x= 15/4
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  3. #3
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    if i multiply all by 3x-7 it would be, 6x+7/3x-7=2? then what would i do?
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  4. #4
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    Quote Originally Posted by andyboy179 View Post
    but im not sure how i would solve this (question in attachment!)
    could someone please point me in the right direction to solving this question!?!

    Click image for larger version. 

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ID:	18912

    Thanks!!
    Dear andyboy179,

    First multiply both sides of the equation by 3x-7. Afterwards you can substract 2x from both sides. Hope you can continue.
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  5. #5
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    so it would be, 6x+7/ 9x-49=2 then 4x+7/ 7x-49=2???
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  6. #6
    Senior Member yeKciM's Avatar
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    Quote Originally Posted by andyboy179 View Post
    if i multiply all by 3x-7 it would be, 6x+7/3x-7=2? then what would i do?
     \displaystyle \frac {2x+1} {3x-7}= 2 \Rightarrow <br />
 \frac {(2x+1)\cdot (3x-7)} {(3x-7) }= 2\cdot (3x-7 ) \Rightarrow 2x+1= 2\cdot (3x-7)

    so you will lose fraction after dividing  \displaystyle \frac {(2x+1)\cdot (3x-7)}{(3x-7)} = (2x+1)

    do you understand ?


    P.S. when said multiply all .... means that you multiply and left and right side of equation !!!
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  7. #7
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    i really don't understand this!! could i do box method with 2x+1 and 3x-7? to get 6x^2-x-6?
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  8. #8
    Senior Member yeKciM's Avatar
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    Quote Originally Posted by andyboy179 View Post
    i really don't understand this!! could i do box method with 2x+1 and 3x-7? to get 6x^2-x-6?
    let's look at this this way ...

     2x = 2 \Rightarrow x = 2/2 = 1

    multiply both sides of equation with 2 and you will have

     4x= 4 \Rightarrow x = 4/4 = 1

    do you see that nothing is changed ?

    now with fractions ....

     \frac {2x}{2} = 1

    because of that under fraction is 2 (can be anything) to lose that fraction you multiply both sides with that whatever is under fraction ....

    in this case multiply with 2

     \frac {2x}{2}\cdot 2 = 1 \cdot 2 \Rightarrow  \frac {2x \cdot 2 }{2} = 1\cdot 2 \Rightarrow   2x = 2 \Rightarrow   x =2/2 = 1
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  9. #9
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    i kinda understand now. you say multiply both sides with 2 so how would i do 2x+1x2? and 3x-7x2?
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  10. #10
    Senior Member yeKciM's Avatar
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    Quote Originally Posted by andyboy179 View Post
    i kinda understand now. you say multiply both sides with 2 so how would i do 2x+1x2? and 3x-7x2?
    you don't multiply by two in your problem there... i just do that with my example to show you that nothing changes if you multiply both sides (or add or divide or ... ) Whatever is "down" in fraction (can't figure out how to write it on English ) you multiply both sides with THAT in your case it's 3x-7

    so you will be free of the fraction



    P.S. when multiplying fraction with number you don't multiply down expression

    \displaystyle  \frac {x+y}{a+b} \cdot 10 = \frac {10x +10y}{a+b}

    but only if you are multiplying fraction with fraction ...

    \displaystyle  \frac {x+y}{a+b} \cdot \frac {10}{3} = \frac {10x+10y}{3a+3b}
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  11. #11
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    OHHH so would it be 6x^2 - 10x -6?
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  12. #12
    Senior Member yeKciM's Avatar
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    Quote Originally Posted by andyboy179 View Post
    OHHH so would it be 6x^2 - 10x -6?
    what would that be ... ????

    lol... don't know what to do now .... probably someone who write better in English can help you maybe that's the problem

    sorry...
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  13. #13
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    would the answer be 2.3?? don't worry i can understand the english but im just finding it hard to pick up how to do these sort of questions!
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  14. #14
    Senior Member yeKciM's Avatar
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    Quote Originally Posted by andyboy179 View Post
    would the answer be 2.3?? don't worry i can understand the english but im just finding it hard to pick up how to do these sort of questions!
    you have solution in my first post (#2)

    it's not problem for you with English ... it's mine

    P.S. you need to get familiar with basic operations with fractions, and on fractions (as multiplying , divide, add , subtract .... ) so you will not have problem piking up stuff like this
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