Answer:
Josh has 26 CDs
Kyle has 38 CDs
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Work Shown:
K = number of CDs Kyle has
J = number of CDs Josh has
K+J = 64 because they have 64 CDs combined
K = J+12 since Kyle has 12 more CDs than Josh does.
We will use substitution to eliminate one variable
K+J = 64
J+12+J = 64 ... replace K with J+12. This is valid because K = J+12
2J+12 = 64
2J+12-12 = 64-12 ... subtract 12 from both sides
2J = 52
2J/2 = 52/2 .... divide both sides by 2
J = 26
Josh has 26 CDs
Use this to find the value of K
K = J+12
K = 26+12
K = 38
Kyle has 38 CDs
As a check, add up the amounts Kyle and Josh has to get
K+J = 38+26 = 64
So this confirms the answer.