# math

posted by on .

At the beginning of the summer molly decided to add a little money into her sayings account every week. After seven weeks her account had \$175. At the end of 15 weeks her account had \$375. Assume that she put the same amount of money into her account every week and will continue to do so.

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Sounds like a good plan.

Was there a question in there somewhere?

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I was trying to find the expression for the problem

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I have to find the equation of the line, but I need the expression to solve it.

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looking at the data, it appears she saved #25 each week. So, after x weeks, her saving y would be

y = 25x

You can work into that by noting that if

y = mx+b

when x=7,
175 = 7m+b

when x=15,
375 = 15m+b

so, 8m = 200
m = 25

Now you have

y = 25x+b
plugging either point shows that b=0, so

y = 25x

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How much was in her account four weeks after she began saving?

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Oops wrong question
When she started saving money, 203 shopping days were left until Christmas. How much money was in her account at Christmas?

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well, you have the equation. How many weeks from the time she started saving, until Christmas? \$25/week, babe.

I assume you know how many days per week . . .

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Thank you I got it....so helpful

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I have that same question but every time I try to put the expression it says it's wrong can you please tell me the expression you used??