Respuesta :

chatterjees25

Answer:

25 quarters, 5 half dollars

Step-by-step explanation:

let a = the number of half dollars in the jar

and b = the number of quarters

a + b = 30

0.5a + 0.25b = 8.75

multiply the second equation by -2 to get

-a - 0.5b = -17.5

Now add the new equation and the first to eliminate h

a + b = 30

-a - 0.5b = -17.5

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0.5b = 12.5

b = 25

There are 25 quarters, so there must be 5 half dollars

Answer:

Step-by-step explanation:

Let half dollars be d and quarters be q

d + q = 30 thus, q = 30 - d

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

0.5d + 0.25q = 8.75 substitute for q:

0.5d + 0.25(30 - d) = 8.75

0.5d + 7.5 - 0.25d = 8.75

0.25d = 1.25

d = 5 so there are 5 half dollars in the jar

Therefore, there are 30 - 5 = 25 quarters in the jar

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Check:

25 x 0.25 = 6.25

5 x 0.5 = 2.5

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Total . . 8.75 Correct

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