Answer:
quarters = 68
nickels = 16
Step-by-step explanation:
Setting up a system of equations and using substitution to solve for each variable will give you the number of quarters and nickels:
q = number of quarters
n = number of nickels
q + n = 84
0.25q + 0.05n = 17.80
Solve the first equation for 'n':
n = 84 - q
Substitute the expression '84 - q' for 'n':
0.25q + 0.05(84 - q) = 17.80
Distribute: 0.25q + 4.2 - 0.05q = 17.80
Combine like terms: 0.20q + 4.2 = 17.80
Subtract '4.2' from both sides: 0.20q + 4.2 - 4.2 = 17.80 - 4.2 or 0.2q = 13.60
Divide both sides by 0.2: 0.2q/0.2 = 13.60/0.2
Solve for 'q': q = 68
Use q = 68 to solve for n:
n = 84 - 68 = 16
