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I'm stuck and can't get out.

  1. Nov 28, 2003 #1
    I'm stuck can anybody help me? (Note: I'm looking for the length.)

    1,800cc-72cm=L

    What do I do next?
     
  2. jcsd
  3. Nov 28, 2003 #2

    chroot

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    Well, what you've posted does not make sense. You cannot subtract a length (cm) from a volume (cc). Perhaps you can show us the WHOLE problem?

    - Warren
     
  4. Nov 28, 2003 #3
    Well maybe I haven't got it written out right. Can I give you the problem and you work it out and show me how to do it?
     
  5. Nov 28, 2003 #4

    chroot

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    Like I just said, yes, please post the entire problem.

    - Warren
     
  6. Nov 28, 2003 #5
    Here it is.

    How long must a rectangular box be in oder to hold 1,800 cubic centimeters if its width is 12 centimeters and its height is 6 centimeters?
     
  7. Nov 28, 2003 #6

    chroot

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    Okay, you've already posted this once. Why did you start a new thread on it?

    Here's how to solve it:

    [tex]\begin{equation*}
    \begin{split}
    V &= w \cdot l \cdot h\\\\
    l &= \frac{V}{w \cdot h}\\\\
    l &= \frac{1,800}{12 \cdot 6}
    \end{split}
    \end{equation*}
    [/tex]

    Does this make sense?

    - Warren
     
  8. Nov 28, 2003 #7
    Let me see if I've got this straight.

    When "w" and "h" are brought arcross the "=" sign, the oppisite must be done.

    [itex] V=l*w*h [/itex]

    [itex] \frac {V}{w*h}=l [/itex]

    Right?
     
  9. Nov 28, 2003 #8

    chroot

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    It's easier to think about it this way: performing the same operation to both sides of an equation does not change the equation's validity.

    In other words, if you have an equation like [itex]a=b[/itex], adding one to both sides of it does not change its truth: [itex]a+1=b+1[/itex] is also true.

    In the case of the equation [itex]V = l \cdot w \cdot h[/itex], you can divide both sides by [itex]w \cdot h[/itex] and not change the equation's valitiy.

    [tex]\begin{equation*}
    \begin{split}
    \frac{V}{w \cdot h} &= \frac{l \cdot w \cdot h}{w \cdot h}\\\\
    \frac{V}{w \cdot h} &= l
    \end{split}
    \end{equation*}[/tex]

    - Warren
     
  10. Nov 28, 2003 #9
    I see what you mean. So my answer is going to be [tex]l &= \frac{1,800}{12 \cdot 6}\end{split}\end{equation*}[/tex]?
     
  11. Nov 28, 2003 #10

    chroot

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    Didn't I already say that?

    - Warren
     
  12. Nov 28, 2003 #11
    Thanks! You've been a real good help Dude!
     
  13. Nov 28, 2003 #12

    chroot

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    Anytime. :smile:

    - Warren
     
  14. Nov 30, 2003 #13

    uart

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    Well fisrt thing I'd do is to get that X-Ray vision tested there Superman. ;)

    Looks to me like when you copied the "answer" of L = 1800cc - 72 cm from whoever that you misread a divide symbol for a minus symbol.
     
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