Finance Charges and Computers! Help!

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

$d-l=1000$

and the finance charges were:

$0.06~d+0.095~l=641.25$

Now solve the simultaneous equations.

RonL