Question

Greg bought a desktop computer and a laptop computer. Before finance charges, the laptop cost $300 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 7% per year. The total finance charges for one year were $365. How much did each computer cost before finance charges?Desktop: $Laptop: $

Answer 1

Greg bought a desktop computer and a laptop computer.

Before finance charges, the laptop cost $300 more than the desktop.

Let Desktop cost be x

Then Laptop cost be x + 300

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 7% per year.

Interest on desktop = 0.09x

Interest on laptop = 0.07 (x+300)

The total finance charges for one year were $365:

`\begin{gathered} \text{Interest}+\text{Interest = }Interest \\ 0.09x+0.07(x+300)=365 \\ 0.09x+0.07x+21=365 \\ \text{collect like terms} \\ 0.16x=365-21 \\ 0.16x=344 \\ x=2150 \end{gathered}`

Therefore the cost of the desktop = $2150

and the cost of the laptop = $2150+300 = $2450