Question 747038
Using x = dimes and y = quarters

    x  +  y  = 17  ...1
   10x + 25y = 215 ...2

Multiply (1) by 10

   10x +  10y = 170 ...3
   10x +  25y = 215 ...2

 Subtract (3) from (2)

          15y = 45

            y = 3
Substitute y = 3 in (1)

       x + y = 17
       x + 3 = 17
           x = 17 - 3
           x = 14
Therefore 14 dimes and 3 quarters
            = $2.15