Sonji has $5.25 in nickels and dimes.The coin value can be modeled by the equation 0.10 d plus 0.05 n equals 5.25, where d represents the number of dimes and n represents the number of nickels. If Sonji has 21 dimes, how many nickels does she have?
First .10*21 is $2.10 so we can subtract so 5.25-2.10 is 3.15 so we know we have to get nickels so 3.15/.5 is 63 so the answer is C sonji has 63 nickels