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6. A cashier has 25 coins consisting of nickels, dimes, and quarters with a value of $4.90. If the
number of dimes is 1 less than twice the number of nickels, how many of each type of coin
does she have?
write and solve 3x3 systems

Respuesta :

Answer:

3 nickels & 5 dimes & 17 quarters

Step-by-step explanation:

dimes=d

nickels=n

quarters=q

0.05n + 0.10d + 0.25q=$4.90

d=n x 2 -1

q=25-d-n

q=25-(2n-1)-n=25-2n + 1-n=26-3n

so going back to the first equation

0.05n + 0.10d + 0.25q=$4.90

0.05n + 0.10(2n-1) + 0.25(26-3n)=$4.90

0.05n + 0.20n -0.1 + 6.5 - 0.75n =$4.90

-0.5n+6.4 =$4.90

-0.5n=-1.5

n=3

d=2n-1=2*3-1=5

q=26-3n = 26- 3*3=17

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