Solution:
According to the problem, the laptop costs $450 less than the desktop. Let x the cost of the laptop, then we get the following equation:
[tex]x\text{ + 450 = cost of the desktop}[/tex]now, the total finance charge of $409 is from 9% of the cost of the laptop and 6.5% of the cost of the desktop. According to this, we get the following equation:
[tex]0.09(x)+0.065(x+450)=409[/tex]Applying the distributive property, we get:
[tex]0.09x+0.065x+29.25=409[/tex]now, placing like terms on each side of the equation, we get:
[tex]0.09x+0.065x=409-29.25[/tex]this is equivalent to:
[tex]0.155x\text{ = 379.75}[/tex]solving for x, we get:
[tex]x\text{ = }\frac{379.75}{0.155}=2450[/tex]this means that:
The cost of the laptop is x = 2450
and
The cost of the desktop is x+450 = 2450 +450 = 2900.
So that, we can conclude that the correct answer is:
Cost of the laptop = 2450
Cost of the desktop =2900.