How many types of CD'S should be sent

a company sells recordable CD'S for 80 cents each and play-only CD'S for 60 cents. the company recieves $76 for an order of 100 CD'S : however, the customer neglected to specify how many of each type to send. determine the number of each type of CD's the should be sent.

Let:

x = # of recordable CD's
y = # of play-only CD's

Here:

.8x + .6y = 76.00
x + y = 100

We can multiply the first function by 10 to get:

8x + 6y = 760
x + y = 100

Then, by elimination method:

8x + 6y = 760
-6(x + y = 100)

8x + 6y = 760
-6x - 6y = -600

2x = 160
x = 80

Finally, substitute that x value for either equation and solve for y.

80 + y = 100
y = 100 - 80
y = 20

Therefore, 80 recordable CD's and 20 play-only CD's should be sent to achieve $76 and 100 CD's.

I hope this helps!