wrighting systems of equations

Question

Xavier has 60 coins in a jar, all dimes and quarters. The total value of the coins adds up to be $10.95.  Write a system of equations then Determine the number of quarters, q, and the number of dimes, d, he has in a jar.

Answer 1

D+Q = 60

10D +25Q = 1095

10D+10Q = 600 subtract to eliminate one variable

15Q = 495

Q = 495/15 = 33 quarters

D = 60-33 = 27 dimes

.10(27) + .25(25) = 2.7 + 8.25 = $10.95