Word problem

Bigsfc

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Nine times a number is 30 more than three times that number. Find the number
 

Subhotosh Khan

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Bigsfc said:
Nine times a number is 30 more than three times that number. Find the number
Assume that the number = N

"Nine times a number" ? 9*N

"Three times that number" ? 3*N

"30 more than three times that number" ? 3*N + 30

Now what.....
 

Bigsfc

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i am totall confused
 

Bigsfc

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I had 9x =45 3x=15 x=5
 

Subhotosh Khan

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Bigsfc said:
I had 9x =45 3x=15 x=5
How did you get those numbers?
 
J

JeffM

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Bigsfc said:
Nine times a number is 30 more than three times that number. Find the number ...
i am totall confused ...I had 9x =45 3x=15 x=5
Subhotosh Khan used N instead of x for the unknown. The choice of letters to stand for unknowns is arbitrary so you need to be a bit flexible. He showed you how to set up the problem without solving it for you. He was hoping you would do:

9N = (30 + 3N).
9N - 3N = 30.
6N = 30
N = 5.

Same answer as you got, but there is a logical route to get there. If you make a mistake in an answer such as the one that you gave, you will get no partial credit because no one knows how you arrived at the answer. (Of course some teachers do not give partial credit.)

This site can be a great resource for students, but it will be much more effective for you if you both present the problem and your work UP TO THE POINT where you got stuck. That way we can help you better.
 
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