Answer:
CD = 10$
Cassette = 1$
Step-by-step explanation:
ok, time to use some variables
C = CD
S = Cassette
2c + 5s = 25$
1c + 15s = 25$
the second equation has 1 less CD and 10 more Cassettes, therefore 1c = 10s
Now we can calculate how many Cassettes we can buy
1c - 1c = 0c
15s + 10s = 25s
This means that 25s = 25$
therefore 1s = 1$
since we know that 10s = 1c, and 1s = 1$, then we can figure out how many dollars the CD is
1c = 10s = 10$
1c = 10$
Variables are helpful :)