Algebra
posted by Christina .
Sally's collection of quarters and dimes contains $32.85. There are 171 coins in all. How many quarters and dimes are in Sally's collection?
Can you show me the two equations you got and explain
Thanks

25 Q + 10 D = 3285 (the total number of cents)
Q + D = 171 (the total number of coins)
To solve, multiply the second equation by 10.
10 Q + 10D = 1710
Now subtract one equation from the other.
15 Q = 1575
Q = 105
D = 171  105 = 66