Answer:
The cost of desktop before finance charge was $1750.
The cost of laptop before finance charge was $1900.
Step-by-step explanation:
Let us assume this is a simple interest scenario.
Let D be the cost of desktop
Let L be the cost of laptop
Given- the laptop cost $150 more than the desktop.
So,
The total finance charge for 1 year is given by :

Substituting the value of L here, we get;

=>
=> 
=> 
=> 
D = $1750
As
So, 
L = $1900
We can check this :

=> 
=> 
So, the cost of desktop before finance charge was $1750.
The cost of laptop before finance charge was $1900.