Answer:
There are 33 quarters and 47 dimes
Step-by-step explanation:
Let the number of quarters be q.
Let the number of dimes be d.
There are 80 coins in total. Therefore:
q + d = 80 ________(1)
The total value of coins is $13.
The value of a quarter is $0.25 and the value of a dime is $0.10. This means that:
0.25q + 0.10d = 13 _____(2)
We have a system of equations:
q + d = 80 ________(1)
0.25q + 0.10d = 13 ____(2)
From (1):
q = 80 - d
Put this in (2):
0.25(80 - d) + 0.10d = 13
20 - 0.25d + 0.10d = 13
Collecting like terms:
-0.15d = 13 - 20
-0.15d = -7
d = -7 / -0.15
d ≅ 47
Therefore:
q = 80 - 47 = 33
There are 33 quarters and 47 dimes.
Answer:
0.062
Step-by-step explanation:
(3.1)(0.02)=0.062




Multiply the numbers.
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Combine multiplied terms into a single fraction.
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Subtract 8 from both sides of the equation.


Multiply all terms by the same value to eliminate fraction denominators.

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Cancel multiplied terms that are in the denominator.
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Multiply the numbers.
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Divide both sides of the equation by the same term.


Simplify.

Solution.
.


ノシ

Part B: It would be 8x+24. You get 4x+12 and double(times 2) it, it would be 8x+24.
Part C: Yes, because the relationship between the ratio would always be proportional.
I would think it to be A because 8/12 can be simplified into 3/4