Explanation:
Let's assign variables to represent the cost of a computer disk and a notebook. Let's say the cost of a computer disk is "x" dollars, and the cost of a notebook is "y" dollars.
According to the given information:
3 computer disks + 5 notebooks = $7.50 ...(1)
4 computer disks + 2 notebooks = $6.50 ...(2)
Now, we can set up a system of equations based on the given information:
Equation 1: 3x + 5y = 7.50
Equation 2: 4x + 2y = 6.50
We can solve this system of equations to find the values of x and y.
Multiplying Equation 1 by 2 and Equation 2 by 5 to eliminate the y variable, we get:
6x + 10y = 15 ...(3)
20x + 10y = 32.50 ...(4)
Subtracting Equation 3 from Equation 4, we eliminate the y variable:
20x + 10y - (6x + 10y) = 32.50 - 15
14x = 17.50
Dividing both sides by 14:
x = 17.50 / 14
x = 1.25
Therefore, the cost of 1 computer disk is $1.25.