Jessica has 9 more nickels then dimes, and the total value of her coins is $1.50. how many nickels does she have? let n represent the number of nickels.

a. 0.10n+0.05(n+9)=1.50
b. 0.10(n-9)+0.05n=1.50
c. 0.10(n+9)+0.05n=1.50
d. 0.10n+0.05n+9=1.50