SOLUTION: word problem a cashier has 25 coins. She has nickels, dimes and quarters. The total amount is $4.90. The dimes are 1 less than twice the number of nickels. I need to show the MATR

Algebra ->  Matrices-and-determiminant -> SOLUTION: word problem a cashier has 25 coins. She has nickels, dimes and quarters. The total amount is $4.90. The dimes are 1 less than twice the number of nickels. I need to show the MATR      Log On


   

Question 881698: word problem
a cashier has 25 coins. She has nickels, dimes and quarters. The total amount is $4.90. The dimes are 1 less than twice the number of nickels. I need to show the MATRIX, solve the problem and write a sentence at the end of the problem explaining the answer.
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
n, d, q, for nickels, dimes, quarters.

d=-1%2B2n;
n%2Bd%2Bq=25;
0.05n%2B0.10d%2B0.25=4.90;
Changing to adjust the form of the first equation,
-2n%2Bd=-1
2n-d%2B0q=1


Resulting Matrix:


Best to multiply the third row by 100 so you have all integers for the matrix:


... and divide row 3 by 5 to have the smallest integers:


Can you continue what you need to do from here?