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# Alexandra earns \$125 from her paper route each month but she spends about & 20 each 0n personal expenses s. To pay for her school trip that cost

\$800, about how many months will it take her to save enough money for the trip. Explain?

Oct 3rd, 2015

Let's write down what we know:

We know Alexandra earns \$124 from her paper route each month.

We know that veronica needs to work x amount of months. So let's call x=the number of months.

We know that she spends 20 dollars every month on personal expenses.

We know that her school trip is \$800 dollars.

Our equation will take the form of solving for the amount of months by the following.

800=124x-20x

To make sure we have our equation right, let's do an example of month 1.

800=124(1)-20(1)=104

800-104=696.

This is logical since we would have gained 124 dollars but lost 20 of it..So in other words 104 dollars is the profit every month.

So, let's look at our original equation.

800=124x-20x (we need to solve for x) First let's simplify the right hand side

800=104x  (divide by 104 from both sides)

x=7.69

Since we can have a fractional month, we round up.

x=8.

Therefore, Alexandra has to save for 8 months to have enough for her trip.

If you wanted to think about it in a different way:

You notice that she gains 124 dollars every months, but spends 20 of it every month too. So you could subtract the two numbers and get

104.

So she earns 104 per month. You can still have x=the number of months, and so 104x=800. (it is just quicker way of getting to the solution).

Sep 16th, 2015

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Oct 3rd, 2015
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Oct 3rd, 2015
Dec 6th, 2016
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