Answer:
There are 24 nickels
Step-by-step explanation:
Let x represent the number of nickels
Let y represent the number of quarters
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Value Value
Type Number of of
of of each all
Coin Coin Coin Coin
—————————————————————
Nickels | x | $0.05 | $0.05x
Quarters | y | $0.25 | $0.25y
—————————————————————
Totals 28 ——— $2.20
•••••••••••••••••••••••••••••••••••••••••••••••••
The first equation comes from the “Number of coins” column.
(Number of nickels) + (Number of quarters) = (total number of coins)
Equation: x + y = 28
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The second equation comes from the “value of all coins” column.
(Value of all nickels) + (Value of all quarters) = (Total value of all coins)
0.05x + 0.25y = 2.20
Remove the decimals by multiplying each term by 100:
5x + 25y = 220
—————————————————————
So we have the system of equations:
{x + y = 28
{5x + 25y = 202
Solve by substitution. Solve the first equation for y:
x + y = 28
y = 28 - x
Substitute (28 - x) for y in 5x + 25y = 220
5x + 25 (28 - x) = 220
5x + 700 - 25x = 220
-20x + 700 = 220
-20x = -480
x = 24
The number of nickels is 24.
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Substitute in y = 28 - x
y = 28 - (24)
y = 4
The number of quarters is 4.
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Checking:
24 nickels is $1.20 and 4 quarters is $1.00
That’s 28 coins.
Indeed $1.20 + $1.00 = $2.20
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Answer: 16 hours
Step-by-step explanation: divide 25 by 5. That’s 5. Multiply 5 by 200. Which is 1000. Divide that by 60 (seconds in one minute). 16.67 is your android.
To find their mph:
192/3.5 = 54.857
So to answer how many miles they could drive at this rate in 6 hours
54.857 * 6 = 329.142 miles
Answer:
92/32
Step-by-step explanation:
Since the formula for volume is length x width x height, and the formula for area is length x width, an expression you could use is 92/32. This divides the volume by the area, which may help find the height.
Not very confident about this answer, but I hope this helps?
56 -----8
x-----3
x=56*3/8=21
it can be done also like this:
c=km
56=k*8
k=56/8=7
c=7m , so c= 7*3=21