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Homework Help: Help with algebra please

  1. Nov 18, 2004 #1
    Ok, so I feel like a big idiot for having to ask this but, my sister needed help with her algebra homework and I cannot for the life of me remember how to do these. I guess it's just the way the problems are worded. If anyone could help with an explanation for each problem so that I can explain it to her, I would greatly appreciate it.

    1. A student company made some school book covers at a cost of 10 cents each. They sold all but three of them at 15 cents each. Their profit was 90 cents. How many covers did they make.

    2. Nadia has seven more nickels than Dora has dimes. If Dora gives Nadia four of her dimes, then Dora will have the same value of money as Nadia. How much money do they have together.

    3. Acme Appliance Company bought several Model H television sets costing $325.00 each. They gave away one set as a door prize and sold the rest for $399.00 each. If their profit was $1,821.00 , find out how many sets they bought.

    4. Some Booster Club members made cupcakes at a cost of 20 cents each. They sold all but two at 30 cents each. If the clubs profit was $3.00 , how many cupcakes did they make.

    ...stupid word problems, thanks for the help!
  2. jcsd
  3. Nov 18, 2004 #2
    1] profit = revenue - cost

    2] Pretty simple

    Nadia has x+7 amount of coins @ 0.05 value
    Dora has x amount of coins @ 0.1 value
    For the case where:
    Nadia has x+7 amount of coins @ 0.05 and 4 coins @ 0.1 she has the same amount of money as Dora with x-4 amount of coins @0.1

    This is assuming that Nadia didn't have any dimes to begin with, or quarters, or that blasted toonie.


    Well agian.

    Profit = revenue - cost

    In this case they sold x amount of televisions @ 399.99 bones, but bought one more then the sold. So they bought x+1 amount of sets @ $325.00

    This is pretty much the same as the one before it, except they are selling cupcakes and didn't sell two, instead of just one.
  4. Nov 18, 2004 #3


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    Homework Helper

    The idea is to write the data as equations, and then solve them for the unknown variable.

    Let x be the number of covers made.
    Then the costs for making the covers were: 10x cents.
    The money they collected for selling them was: (x-3)15 cents.
    So the profit is the difference between these two and equals 90 cents.
    You can find x from that.
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