Posted by selena on Sunday, March 8, 2009 at 10:33pm.
lavre has sixtyone coins, all of whichare dimes and quaters. if the total value of the coins is $9.85, how many of each kind of coins has she?

grade 9 math!!!!!!!!!! please help  DrBob222, Sunday, March 8, 2009 at 10:49pm
If Q = # quarters
and D = # dimes.
Then
Q+D=61
.25Q+.10D=9.85
=================
Two equations and two unknowns. Solve for Q and D. Check my work.

grade 9 math!!!!!!!!!! please help  Anonymous, Monday, March 9, 2009 at 1:33pm
Q = 25
D = 36
It's a system of linear equations so you can put it into a matrix to solve
let Matrix A be a 2x2 matrix
1 1
.25 .1
and have another matrix, B
61 
9.85
A^1 * B will give you the answer
Answer This Question
Related Questions
 math  lavere has sixtyone coins, all of which are dimes and quaters. if the ...
 5th grade math  I need to use quarters, dimes, nickles and pennies to make the ...
 math  Grandpa has twenty  four coins in his pocket . grandpa gives Sam some ...
 Math  Shirley has 18 coins. One sixth of the coins are quarters, one third of ...
 Math  The cash in the school canteen contains x quarters and (30x) dimes. If ...
 Math  A bag contains forty coins, all of them either 2c or 5c coins. Let there ...
 maths  A bag contained a number of 20cents, 50cents and $1 coins. 1/3 of the ...
 Math  Laverne has sixtyone coins, all of which are dimes and quarters. If the ...
 Acc. Algebra 2  A jar contains 40 coins consisting of dimes and quarters and ...
 4th grade  Bobby has only pennies, dimes, and quarters. One half of Bobby's ...
More Related Questions