Question

A piggy bank contains 70 coins. The coins are dimes and nickels worth $5.50. Use substitution to solve the system of equations to find out how many dimes and nickels are in the piggy bank.

Answer 1

There are 40 dimes and 30 nickels :)

Explanation:

5.50=0.10d+0.05n

70=d+n

how to solve-

n=70-d

5.50=0.10d+0.05(70-d)

5.50 = 0.10d +3.5 -0.05d

5.50= 0.05d+3.5

2=0.05d

d=40

70=d+n

70=40+n

n=30