1. precent problem

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 5% per year, and for the laptop it was 4.5% per year. The total finance charges for one year were$453.75. How much did the desktop computer cost before finance charges?

2. Let's say $\displaystyle x$ $\displaystyle =$ price of desktop (before financing).
Then $\displaystyle x-1000 =$ price of laptop (before financing).

Multiplying by the finance percentages:

$\displaystyle .05x + .045(x-1000) = 453.75$

I'll let you take it from there.

3. I'm still having problems with this type of question, It looks similar to eqasions where you set up ex:
x+y=1000
30x+40y=300
then just simply ad (-30) to the uper portion in order to cancel out aether x or y.

is that what i do here? I'm still lost.

Here's a similar problem I'm dealing with now:
A theater group made appearances in two countries. The hotel charges before tax in the second country were $1000 higher than in the first. The tax on the hotel bill was 8% in the first country and 6.5% in the second. After the trip, the total tax paid on accommodation expenses was$608.75 How much was the hotel bill in the first country before tax?

4. then just simply ad (-30) to the uper portion in order to cancel out aether x or y.

is that what i do here? I'm still lost.
Yes, multiply the first equation by -30.

5. x=3425

that doesnt sound right =/