What is the proper way to work this probelm...4cd =14...c=1/2d=7

What is the right way to wok this problem ?

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- Jan 18th 2009, 06:21 PMLeona_Mariealgebraic expressions
What is the proper way to work this probelm...4cd =14...c=1/2d=7

What is the right way to wok this problem ? - Jan 19th 2009, 03:17 AMdarkness9375
- Jan 19th 2009, 04:35 AMursaQuote:

What is the proper way to work this probelm...4cd =14...c=1/2d=7

What is the right way to wok this problem ?

there are 1 equation and 2 unknown variable

we have to assume 1 variable to get the value of another variable - Jan 19th 2009, 07:14 AMLeona_Mariepuzzled
- Jan 19th 2009, 08:58 AMLeona_Marie4cd=14
- Jan 19th 2009, 09:15 AMmasters
Hi Leona,

I'm not sure that you have stated your question properly. Try and be a little clearer. Use parentheses, separate lines, anything to set apart what it is you are trying to convey.

Looks like your original equation is $\displaystyle 4cd=14$

Then, the second part is ambiguous.

Dose $\displaystyle c=\frac{1}{2}d$ and does $\displaystyle \frac{1}{2}d=7$?

If that's the case, then substitute 7 for c and solve for d. But I'm not sure that's the case. - Jan 19th 2009, 09:43 AMLeona_Marie
- Jan 19th 2009, 09:56 AMmasters
Ok, Leona, I think you intend to state the problem this way.

$\displaystyle 4cd=14$

$\displaystyle c=\frac{1}{2}$

Substituting, we get

$\displaystyle 4\left(\frac{1}{2}\right)d=14$

$\displaystyle 2d=14$

$\displaystyle \frac{2d}{2}=\frac{14}{2}$

$\displaystyle d=7$

Checking, we substitute the values we found for**c**and**d**back into the original equation and get:

$\displaystyle 4\left(\frac{1}{2}\right)(7)=14$

$\displaystyle 4(3.5)=14$

$\displaystyle 14=14$ - Jan 19th 2009, 10:40 AMLeona_Marie
- Jan 19th 2009, 10:48 AMmasters