Sunday

March 29, 2015

March 29, 2015

Posted by **selena** on Sunday, March 8, 2009 at 10:33pm.

- grade 9 math!!!!!!!!!! please help -
**DrBob222**, Sunday, March 8, 2009 at 10:49pmIf 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 1:33pmQ = 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 sixty-one 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 - 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 (30-x) 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 sixty-one coins, all of which are dimes and quarters. If the...

Acc. Algebra 2 - A jar contains 40 coins consisting of dimes and quarters and ...

Math - Susan has some $2-coins and $5-coins. If there are 18 coins and the total...

Math - Assume that you select 2 coins at random from 5 coins: 3 dimes and 2 ...