A piggy bank contains 100 coins consisting of nickels and dimes. the total value of the coins is $8.50. How many coins of each type does the bank contain?

the bank contains 30 nickels and 70 dimes.

30 Nickels, 70 Dimes

1 nickel (n) = 5 cents

1 dime (d) = 10 cents

total value 850 cents

5n+10d=850 divide both sides by 5

n+2d=170 solving with the system of equations we get

n+2d=170

n+d=100

N=30

D=70