Matthew has a jar of 368 nickels and dimes he has been collecting. The total value ofthe coins is $28.40. How many coins of each type does Matthew have?
d = # dimes value = 10d
n = nickels = 368 - d value = 5 (368-d) summed = 2840
10d + 5 (388-d) = 2840
solve for 'd' ...the # of dimes then # nickels = 368 - d