Question 753784
x = dimes y = quarters
  x + y   = 17.....1
10x + 25y = 230....2
Multiply (1) by 25
25x + 25y = 425 ....3
10x + 25y = 230 ....2
Subtract (2) from (3)
15x       = 195
  x       = 13
Substitute x = 13 in Eq (1)
 x + y = 17
13 + y = 17
     y = 17 - 13
     y = 4
Therefore you have 
:-
13 dimes and 4 quarters
Hope this helps
:-)