Let c = the price of a cd
Let t = the price of cassette tapes
2c+4t=40
3c+5t=55
We could use substitution to solve this system of equations.
2c+4t=40
-2c -2c
__________
4t=40-2c
__________
4
t=10-1/2c
3c + 5(10-0.5c)=55
3c + 50 -2.5c = 55
- 50. -50
________________
0.5c = 5
c = 10
3c + 5t = 55
3(10) + 5t = 55
30 + 5t = 55
-30 -30
____________
5t = 25
t = 5
So, a cd costs $10 and a cassette recording costs $5.
