Ashley has $0.90 in nickels and dimes. The number of dimes is 1 less than twice the number of nickels. Find the number of nickels.
n = # nickels
d = dimes = 2n-1
5 n + 10 (2n-1) = 90
25n -10 = 90
25n = 100
n = 4 d = 2n-1 = 7
+36915 
