A child find 29 nickels and dimes. how many dimes are there if the total value of the coins are $2.10?

X represents nickels

y represents dimes

x+y=29

5x+10y=210

multiply the first equation by - 5 (elimination method)

-5x-5y=-145

then add the two equations together

5y=65

divide 5 from both sides

y=13

13 dimes

Devide 29 by 2.10 and you get 13.8095238 then round off to 13

So there are 13 dimes and 16 nickels

To check the answer just put 13 x 10 + 16 x 5 in a calculator and the answer should be 210