SOLUTION: Stefan has a collection of nickels, dimes, and quarters. in all, he has 24 coins. seven of the coins are quarters. the total value of the collection is $2.90. How many nickles and

Question 825611: Stefan has a collection of nickels, dimes, and quarters. in all, he has 24 coins. seven of the coins are quarters. the total value of the collection is $2.90. How many nickles and how many dimes does he have?
Answer by TimothyLamb(4379) (Show Source): You can put this solution on YOUR website!
---
x + y + z = 24
z = 7
5x + 10y + 25z = 290
---
copy and paste the above standard form linear equations in to this solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
---
solution:
x nickels = 11
y dimes = 6
z quarters = 7
---
system matrix
1 1 1
0 0 1
5 10 25
---
inverse of system matrix
2 3 -0.2
-1 -4 0.2
0 1 0
---
determinant of system matrix = -5
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Solve systems of linear equations up to 4-equations 4-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php
RELATED QUESTIONS
Stefan has a collection of nickels, dimes, and quarters. In all, he has 24 coins. seven... (answered by stanbon)

a coin collection contains nickels dimes quarters there are twice as many dimes as... (answered by dabanfield@earthlink.net)

Cookie has 97 coins in her collection � all either nickels, dimes or quarters. If 77 of... (answered by Edwin McCravy)

Stefan has 42 coins in his collection. The coins consist of nickels, dimes, and quarters. (answered by checkley75)

A collection of 20 coins made up of only nickels, dimes, and quarters has a total value... (answered by solver91311)

A collection of 20 coins made up of only nickels, dimes and quarters has a total value of (answered by ankor@dixie-net.com)

A coin collection of nickels, dimes and quarters has a value of $10. There are twice as... (answered by ewatrrr)

Jonathan has 136 coins in this collection of dimes and quarters. If the coins have a... (answered by ptaylor)

A coin collection contains nickels, dimes, and quarters. There are twice as many dimes as (answered by ikleyn)