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Question 1012631: How can i use linear equations to solve problems
Answer by addingup(3677)   (Show Source):
You can put this solution on YOUR website! You use linear equations to solve problems like this example:
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Calvin has $8.80 in pennies and nickels. If there are twice as many nickels as pennies, how many pennies does Calvin have? How many nickels?
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Solve:
0.01p+0.05n = 8.80 (pennies and nickels total 8.80)
n = 2p (there are twice as many nickels as there are pennies so to make them equal you have to double the number of pennies) Let's use this value for n in the equation above:
0.01p+0.05n = 8.80 Substitute for n:
0.01p+0.05(2p)= 8.80
0.01p+0.10p = 8.80
0.11p= 8.80 Divide both sides by 0.11:
p = 8.80/0.11= 80
He has 80 pennies and the problem says he has twice as many nickels, so he has:
80*2= 160 nickels
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Proof:
80*0.01= 0.80
160*0.05= 8
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Total... 8.80 We have the correct answer.
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This was quite a bit of writing on my part to provide you with a lesson. I hope you read through my example a few times so you understand the linear problem solving process.
J
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