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.
————————————————————
Substitute in y = 28 - x
y = 28 - (24)
y = 4
The number of quarters is 4.
————————————————————
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:
d
Step-by-step explanation:
i think
Sum of interior angle of polygon: S = (n-2) * 180°,
where n is number of sides and where S is total degrees.
With 6 sides, n = (6-2)*180 = 720°
Then set all of the interior equations equal to the sum, or
720 = 5x + 4x+2 + 5x+6 + 2x-2 + 3x+5 + x-10
720 = 20x + 1
719 = 20x
x = 
= 35.95
Hello!
To find how much less Marvin pays per liter using his loyalty card, we can subtract the discounted value from the original value.
1.679 - 1.439 = 0.24
Therefore, Melvin pays 0.24 dollars less per liter using his loyalty card.
