Step-by-step explanation:
Let's let [tex]T[/tex] represent the cost of tapes, and [tex]C[/tex] be the cost of CDs.
From the problem statement, we can create the following two equations:
[tex]4T + 2C = 46[/tex]
[tex]3T + C = 28[/tex]
To solve this system of equations, we can solve for [tex]C[/tex] in the second equation and substitute into the first equation to get the value of [tex]T[/tex]:
[tex]3T + C = 28[/tex]
[tex]C = 28 - 3T[/tex]
Substitution:
[tex]4T + 2(28 - 3T) = 46[/tex]
[tex]4T + 56 - 6T = 46[/tex]
[tex]-2T = -10[/tex]
[tex]T = 5[/tex]
Now that we know the cost of the tapes, we can plug this value into either equation to get the cost of CDs:
[tex]4T + 2C = 46[/tex]
[tex]4(5) + 2C = 46[/tex]
[tex]20 + 2C = 46[/tex]
[tex]2C = 26[/tex]
[tex]C = 13[/tex]
or
[tex]3T + C = 28[/tex]
[tex]3(5) + C = 28[/tex]
[tex]15 + C = 28[/tex]
[tex]C = 13[/tex]
Therefore, the cost of a tape is [tex]$5[/tex] and the cost of a CD is [tex]$13[/tex].