Question 12709
Let the number of nickels be "x".
Then number of dimes is "35-x".
Value of nickels is (5)x cents.
Value of dimes is (10)(35-x)= (350 -10x) cents.
EQUATION:
Value of nickels + Value of dimes is 330 cents
   5x +350-10x = 330
          -5x = -20
            x = 4 (number of nickels)
        35-x  = 31 (number of dimes)

Cheers,
Stan H.