We need 2 equations here [more coming]
Total amount of money = 2.35 dollars
Each nickel is worth 0.05 cents (let X denote nickels)
Each dime is worth 0.10 cents (let Y denote dimes)
Total amount of coins is 32
So we get the following:
0.05x + 0.10y = 2.35
x + y = 32 --> y=32-x (plug this into the 1st equation)
0.05x + 0.10y = 2.35
0.05x + 0.10(32-x) = 2.35
0.05x + 3.2 - 0.10x = 2.35
-0.05x = -0.85
x= 17
Since we know that x + y = 32
(17) + y = 32 --> y =15
Therefore, we have 17 nickels and 15 dimes.
2007-12-31 07:54:52
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answer #1
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answered by ¿ /\/ 馬 ? 7
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n = nickels
d = dimes
total value = value of nickels + value of dimes
2.35 = .05n + .10d
Total coins = # of nickels + # of dimes
32 = n + d
We want to substitute one equation into the other to get it down to 1 variable.
32 = n + d
32 - d = n
2.35 = .05(32 - d) + .10d
2.35 = 1.6 - .05d + .10d
.75 = .05d
15 = d
15 dimes
15 + n = 32
n = 32 - 15
n = 17
17 nickels
2007-12-31 15:59:09
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answer #2
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answered by Anonymous
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5n + 10d = 235
n + d = 32
so half of knowing where to start - is expressing our problem
so let's isolate one of the coins from the second equation
by subtracting n from both sides
n-n+d = 32-n
therefore
d = 32 - n (the number of dimes equals the total number minus the number of nickels) so easy - yeah!
now substitute into the first equation
5n + 10(32-n) = 235
5n + 320 - 10n = 235
320 - 5n = 235
subtract 235 both sides
320- 235 - 5n = 235 - 235
85 - 5n = 0
add 5n to both sides
85 = 5n
and you have it from here
once u get n =
substitute back into the second equation to see how many dimes you have
have a great 2008
2007-12-31 15:57:53
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answer #3
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answered by tom4bucs 7
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Set up a system of equations.
n=nickels
d=dimes
I will be using cents.
1) 235 = 5 * n + 10 * d
2) 32 = n + d
There are many ways to solve this: substitution, matrices, and elimination. I will be using substitution.
n = 32 - d ...(from equation 2)
235 = 5 * (32 - d) + 10 * d ... (substitute for n into equaiton 1)
235 = 160 - 5d + 10d ...(simplify)
75 = 5d
d=15
n=17 (put d into equation 2)
2007-12-31 15:57:35
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answer #4
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answered by Goddard 5
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Nickels = n, Dimes = d
We have two equations:
1) .05n + .1d = 2.35
2) n + d = 32
Manipulate these two equations, eliminate one variable, solve for the remaining variable, then substitute the value of the variable into either equation and find the value of the other variable!
2007-12-31 15:56:40
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answer #5
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answered by =) 1
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32-n=d
5n+10d=235
n=17
d=15
2007-12-31 15:56:11
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answer #6
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answered by Mark L 3
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N + D = 32
5N + 10D = 245
divide both sides by 5
N + 2D = 49
subtract the first equation
D = 17
plug into the first equation
N + 17 = 32
N = 15
check .75 + 1.70 = $2.45
2007-12-31 15:56:09
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answer #7
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answered by holdm 7
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