How to Correctly Solve L = 1800cc - 72cm?

[Superman89]

I'm stuck can anybody help me? (Note: I'm looking for the length.)

1,800cc-72cm=L

What do I do next?

 

[chroot]

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

 

[Superman89]

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?

 

[chroot]

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

- Warren

 

[Superman89]

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?

 

[chroot]

Originally posted by Superman89
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?

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

 

[Superman89]

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?

 

[chroot]

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

 

[Superman89]

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]?

 

[chroot]

Didn't I already say that?

- Warren

 

[Superman89]

Thanks! You've been a real good help Dude!

 

[chroot]

Originally posted by Superman89
Thanks! You've been a real good help Dude!

Anytime.

- Warren

 

[uart]

Originally posted by Superman89
I'm stuck can anybody help me? (Note: I'm looking for the length.)

1,800cc-72cm=L

What do I do next?

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.