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Topic: need help to solve algebra problem
Replies: 4   Last Post: May 31, 2005 8:47 AM

 Messages: [ Previous | Next ]
 Barb Knox Posts: 578 Registered: 12/6/04
Re: need help to solve algebra problem
Posted: May 31, 2005 7:21 AM

In article <d7hecb\$p4u\$1@news.hispeed.ch>,
"lionel vulliemin" <lionel.vulliemin@urbanet.ch> wrote:

>Good morning, I come swiss, and hoe that someone could help me with this
>problem:
>we have 2 summ put in an account for a total of 20.000 \$ .
>the first have t%, and give 1.080 \$ interest par year.
>the second have (t+1)% , and it give 800 \$ par year.
>find the two capital ?
>I don't now how to find the result ! on the book, it's writing the first one
>have a capital of 12.000\$, and the second have 8.000\$...... could you give
>me the way to find these 2 capitals.
>Thank you very much

Firstly, check the book answer; if you can't do that then either the book is
wrong (possible but unlikely) or you don't adequately understand the problem:
\$12000 * t/100 = \$1080, so t must = 9; then
\$ 8000 * (9+1)/100 should = 800, which it does.

Now, setting up the equations, let x the capital amount at the t% rate;
then (20000 - x) is the amount at the (t+1)% rate, so
x * t/100 = 1080; and
(20000 - x) * (t+1)/100 = 800.
This is 2 equations in 2 unknowns, which you should be able to reduce to 1
equation in 1 unknown by substitution (by solving the first equation for x
or for t -- your choice).

Then solve that final equation (which will be a quadratic) for its 1
unknown, and use that value in the first equation to calculate the other
unknown.

--
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| BBB b \ Barbara at LivingHistory stop co stop uk
| B B aa rrr b |
| BBB a a r bbb | Quidquid latine dictum sit,
| B B a a r b b | altum viditur.
| BBB aa a r bbb |
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Date Subject Author
5/31/05 Barb Knox
5/31/05 Vincent Johns
5/31/05 lionel vulliemin