Anne has 20 coins in her pocket consisting of nickels and dimes only. The total value of the coins is $1.45. How many nickels and how many dimes does she have? (Let x represent the number of nickels and y represent the number of dimes.)

Answer 1

d represents Dimes
n represents Nickles
Total number of coins;
d + n = 20, n = (20-d) ...1
Total value of coins;
10d + 5n = 145 ...2

substitute equation 2 with equation 1 for n,
10d + 5(20-d) = 145,
10d + 100 - 5d =145,
10d -5d = 145 -100, d = 45/5 = 9 dimes
20 - 9 = 11 nickles

Answer 2

wrong