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3 years ago

5n is the mean of three numbers 391, n and n-1, find n

Mathematics

1 answer:

Orlov [11]3 years ago

3 0

Answer:

Step-by-step explanation:

5n = Mean of three numbers

391 = 1st number

n = 2nd number

n - 1 = 3rd number

Therefore, to solve for x, we can write this equation:

(391 + n + n - 1)/3 = 5n

391 + 2n - 1 = 15n (Lowest Common Denominator is 3)

2n - 15n = -390 (Like terms)

-13n = -390

n = -390/-13

Proof of n= 30 is correct:

(391 + n + n - 1)/3 = 5n

(391 + 30 + 29)/3 = 5 * 30

450/3 = 150

150 = 150

We proved n = 30 is correct

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Answer:

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Answer:

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Answer:

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Step-by-step explanation:

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