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Math Help - Can someone please explain

  1. #1
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    Can someone please explain

    Can someone please explain in detail so I understand how x-5/2 - x-4/3 = x-3/2 - (x-2)
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  2. #2
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    Quote Originally Posted by quarinteen View Post
    Can someone please explain in detail so I understand how x-5/2 - x-4/3 = x-3/2 - (x-2)
    Please use brackets so that the terms in your expression are not ambiguous. eg. Is x - 5/2 meant to be (x - 5)/2 or x - (5/2) etc.
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  3. #3
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    Sorry im a programmer x-5 over 2 - x-4 over 2 = x-3 over 2 - (x-2) how does this = -5 over 2 so 5/2
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  4. #4
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    \dfrac{x-5}{2} - \dfrac{x-4}{3} = \dfrac{x-3}{2} - (x-2)

    Is this it?
    Last edited by mr fantastic; September 29th 2010 at 04:10 AM. Reason: Fixed a mistake caused by the OP making a mistake in post #3.
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  5. #5
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    You're a programmer? Then you should understand even more how important parentheses are!

    But you still refuse to use parentheses. "x- 4 over 2" could mean (x- 4)/2 or x- (4/2).
    Also, originally, you had "x- 4/3" but now you say "x- 4 over [b]2[/sup]"!

    In any case, if it were either x- (4/2) on the left or (x- 4)/2, the two sides can't be equal, the "x" would cancel on the left.

    I suspect you mean (x- 5)/2- (x- 4)/3= (x- 3)/2- x- 2 but that is still not true! On the left, when you combine the fractions, you will have
    \frac{3x- 15}{6}- \frac{2x- 8}{6}= \frac{x- 7}{6}
    but on the right \frac{x- 3}2- x- 2= \frac{x- 3}{2}- \frac{2x+ 2}{2}= -\frac{x- 5}{2}

    What you have written simply cannot be true.
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  6. #6
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    Quote Originally Posted by HallsofIvy View Post
    You're a programmer? Then you should understand even more how important parentheses are!

    But you still refuse to use parentheses. "x- 4 over 2" could mean (x- 4)/2 or x- (4/2).
    Also, originally, you had "x- 4/3" but now you say "x- 4 over 2[/sup]"!

    In any case, if it were either x- (4/2) on the left or (x- 4)/2, the two sides can't be equal, the "x" would cancel on the left.

    [b] I suspect you mean (x- 5)/2- (x- 4)/3= (x- 3)/2- x- 2 but that is still not true! On the left, when you combine the fractions, you will have
    \frac{3x- 15}{6}- \frac{2x- 8}{6}= \frac{x- 7}{6}
    but on the right \frac{x- 3}2- x- 2= \frac{x- 3}{2}- \frac{2x+ 2}{2}= -\frac{x- 5}{2}

    What you have written simply cannot be true.
    It would appear that the question is meant to be:

    Solve \dfrac{x-5}{2} - \dfrac{x-4}{3} = \dfrac{x-3}{2} - (x-2).

    Most programmers understand the GIGO principle (Garbage in, garbage out) ....

    My advice to the OP is to get each side over a common denominator of 6, simplify the resulting numerators and then equate. You end up with x - 7 = -3x + 3 and solving for x is simple.
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  7. #7
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    Quote Originally Posted by quarinteen View Post
    Can someone please explain in detail so I understand how x-5/2 - x-4/3 = x-3/2 - (x-2)
    Next time, use BRACKETS in order to show properly: (x - 5)/2 - (x - 4)/3 = (x - 3)/2 - (x - 2)
    There is a huge difference (as example) between x - 5/2 and (x - 5)/2
    Take this:
    100 - 20/5 = 100 - 4 = 96
    (100 - 20)/5 = 80/5 = 16 ; do you "get it" now?
    I too am surprised that you're a programmer and didn't know this.
    More so since you stated this on one of your previous posts:
    " I am not in school I haven't been for a while. I was attempting to help a friend got to this problem and its bugging me."

    Can you answer this:
    (x - 5)/2 * 6 = ?
    If not, you need to learn the Algebra basics; can't "teach" that here, sorry.
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