Amy has total of 100 coins that are all dimes and quarters. The amount of money that equals is $21.40
Set up a system of equations and write the matrix equation that describes this situation. Let x = dimes
and y = quarters.

Question

Amy has total of 100 coins that are all dimes and quarters.  The amount of money that equals is $21.40
Set up a system of equations and write the matrix equation that describes this situation.  Let x = dimes
and y = quarters.

stacey · Answer

Since x is the number of dimes, $0.10x is the value of x number of dimes.
Since y is the number of quarters, $0.25x is the value of y number of quarters.
Using the values, we have 0.10x + 0.25y = 21.40

stacey · Answer

Do you see what x+y will equal?

anonymous · Answer

SO the matrix will end up being [1 0.10] [x] = [ 100]
                                                 [1  0.25] [y] = [21.40] ?
Or do i have it backwards?

stacey · Answer

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