Two cds and 4 cassette tapes xosr a total of $40.00. however, 3cds and 5 casette rapes cost $55.00 find the price of each type of recording

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.
   
 

4should be the last one n=4