A change purse contains a total of 100 nickels and dimes. The total value of the coins is $7. How many coins of each type does the purse contain.

x = nickels      5x = AMOUNT of nickels (cents)

100-x = dimes   (10)(100-x) = AMOUNT of dimes (cents)

5x + 10(100-x) = 700 cents

5x + 1000 - 10x = 700 cents

-5x = -300 cents

x = 60 nickels           100 - x = 100 - 60 = 40 dimes

60 nickels and 40 dimes