9514 1404 393
Answer:
 z + y = 52; z - y = 10; z = 31; y = 21; $9.85 total
Step-by-step explanation:
The variables are defined in the problem statement. The equations could be ...
 z + y = 52 . . . . . . total number of coins
 z - y = 10 . . . . . . . 10 more quarters than dimes
These equations can be solved by adding them together.
 (z +y) +(z -y) = (52) + (10)
 2z = 62 . . . . . . . simplify
 z = 31 . . . . . . . . . divide by 2
 31 -10 = y = 21 . . . . find the number of dimes
There are 31 quarters and 21 dimes.
The value of the coins is ...
 31($0.25) +21($0.10) = $7.75 +2.10 = $9.85
