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