Question

jill has $9.96 in nickles,pennies, and dollar bills. she has 12 more pennies than nickles and fove fewer dollar bills than nickles. how many of each does she have?

Answer 1

Number of pennies:P
Number of nickels:N
Number of dollar bills:D
P=N+12
N=D+5
1P+5N+100D=996
^given
Therefore 
P=(D+5)+12
P=D+17
Plug back into main equation
(D+17)+5(D+5)+100D=996
Combine like terms 
106D+42=996
106D=954
D=954/106=9

9 Dollar bills

N=D+5
N=(9)+5=14

14 Nickels

P=N+12
P=(14)+12=26

26 Pennies

26*1+14*5+9*100=996

Final answer:
9 Dollars
14 Nickels
26 Pennies