# Finance Charges and Computers! Help!

• Mar 6th 2008, 08:19 PM
eraser851
Finance Charges and Computers! Help!
Bob bought two computers, one desktop and one laptop. Before finance charges, the laptop cost \$1000 less than the desktop. Bob paid for the computers using two different financing plans. For the desktop the interest rate was 6% per year, and for the laptop it was 9.5% per year. The total finance charges for one year were \$641.25 . How much did the desktop computer cost before finance charges?

I have no idea where to start. Anyone care to guide me through this?
• Mar 7th 2008, 08:16 AM
CaptainBlack
Quote:

Originally Posted by eraser851
Bob bought two computers, one desktop and one laptop. Before finance charges, the laptop cost \$1000 less than the desktop. Bob paid for the computers using two different financing plans. For the desktop the interest rate was 6% per year, and for the laptop it was 9.5% per year. The total finance charges for one year were \$641.25 . How much did the desktop computer cost before finance charges?

I have no idea where to start. Anyone care to guide me through this?

Let \$\displaystyle l\$ be the cost of the laptop and \$\displaystyle d\$ the cost of the desk top, then:

\$\displaystyle d-l=1000\$

and the finance charges were:

\$\displaystyle 0.06~d+0.095~l=641.25\$

Now solve the simultaneous equations.

RonL