Me tony bought a desktop computer and a laptop computer. before finance charges, the laptop cost $450 more than the desktop. he paid for the computers using two different financing plans. for the desktop the interest rate was 9% per year, and for the laptop it was 6 % per year. the total finance charges for one year were $300. how much did each computer cost before finance charges?

Laptop: $2,270

Desktop: $1,820

Step-by-step explanation:

Let L identify the laptop price and D the desktop price.

We can first say:

L = D + 450 ( the laptop cost $450 more than the desktop)

Then we can say:

0.09 D + 0.06 L = 300 (The total finance charges for one year were $300)

Then we substitute L by its value from first equation into the second equation:

0.09 D + 0.06 (D + 450) = 300

0.09 D + 0.06 D + 27 = 300

0.15D = 273 (removed 27 on both sides, and simplified left side)

D = 1,820

The cost of the desktop was $1,820

The cost of the laptop was $2,270 (price of desktop + $450)