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Math Help - inequality question :)

  1. #1
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    inequality question :)

    solve the inequality..

    -35 < 6x + 7 < 1
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  2. #2
    Junior Member shinhidora's Avatar
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    Quote Originally Posted by johnsmith666 View Post
    solve the inequality..

    -35 < 6x + 7 < 1
    First solve -35 < 6x + 7 then solve 6x + 7 < 1
    Your answer is between those 2 answers

    -35 = 6x + 7
    -42 = 6x
    -7 = x

    so everything between -7 (-7 not included) and infinity is a possible answer

    6x + 7 = 1
    6x = -6
    x = -1

    so everything between -1 and - infinity is a possible answer here

    making the final answer between -7 and -1 (both not included)... (I totally forgot how to put this mathematically )

    Edit: something like this... [-7,-1](I think? )
    Last edited by shinhidora; January 5th 2010 at 09:31 AM. Reason: LaTex fail (well I failed... :p)
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  3. #3
    Super Member bigwave's Avatar
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    solve the inequality..

    -35 < 6x + 7 < 1

    isolate the varible in the middle

    -42 < 6x< -6

    divide each term by 6

    -7 < x < -1

    the solution set is [-7,-1]
    Last edited by bigwave; January 5th 2010 at 09:38 AM. Reason: corrected formula
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  4. #4
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    thanksss shinnnndingggg
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  5. #5
    Junior Member shinhidora's Avatar
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    Quote Originally Posted by bigwave View Post
    isolate the varible in the middle

    -42 < 6x< -6

    divide each term by 6

    -7 < x < -1
    Lol, I got owned...

    But this won't always work, will it?

    edit: Use the thanks button :'D
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  6. #6
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    u waatttt?? im confusedd i used both ur answers cos i needed to show working. im doing an AS level paper u see.
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  7. #7
    Super Member bigwave's Avatar
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    if we try to divide each term by a variable it won't work because we do not know the sign.

    i followed an example out of text book which was a similiar problem

    we both have the same answers

    consider multiple replies to the same post a good thing...
    Last edited by bigwave; January 5th 2010 at 09:45 AM. Reason: more info
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  8. #8
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    could u try and do another question for me please .

    express x^2 - 5x +1/4 in the form (x-a)^2 - b

    thanks
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  9. #9
    Senior Member Mukilab's Avatar
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    This AS level is harder then the GCSE papers I've seen...
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  10. #10
    Super Member bigwave's Avatar
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    Cool

    Quote Originally Posted by johnsmith666 View Post
    could u try and do another question for me please .

    express x^2 - 5x +1/4 in the form (x-a)^2 - b

    thanks
    do you know how to "complete the square" on this..
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