For Natural Number m, n if (1 – y)m (1 + y)n = 1 + A1 y + a2 y2 +….. and a1 = a2 = 10, Them (m, n) Is

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Question

For natural number mn if (1 – y)m (1 + y)n = 1 + ay + ay2 +….. and a1 = a2 = 10, them (mn) is

Solution

Correct option is

(35, 45)

   a1 = coefficient of y = n – m = 10……………(i)

   

     (m2 + n2) – (m + n) – 2mn = 20

or  (n – m)2 – 20 = m + n

or   m + n = 102 – 20 = 80 by…………(ii)

solving (i) and (ii), n = 45, m = 35.

Testing

SIMILAR QUESTIONS

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Q9

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Q10

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