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The sum of the coefficients of x^(32) an...

The sum of the coefficients of `x^(32)` and `x^(-17)` in `(x^4- 1/(x^3))^15` is

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To solve the problem of finding the sum of the coefficients of \(x^{32}\) and \(x^{-17}\) in the expansion of \((x^4 - \frac{1}{x^3})^{15}\), we will follow these steps: ### Step 1: Identify the General Term The general term in the binomial expansion of \((p + q)^n\) is given by: \[ T_{r+1} = \binom{n}{r} p^{n-r} q^r \] In our case, \(p = x^4\), \(q = -\frac{1}{x^3}\), and \(n = 15\). Thus, the general term becomes: \[ T_{r+1} = \binom{15}{r} (x^4)^{15-r} \left(-\frac{1}{x^3}\right)^r \] ### Step 2: Simplify the General Term Now, we simplify \(T_{r+1}\): \[ T_{r+1} = \binom{15}{r} x^{4(15-r)} \left(-1\right)^r \frac{1}{x^{3r}} = \binom{15}{r} (-1)^r x^{60 - 4r - 3r} = \binom{15}{r} (-1)^r x^{60 - 7r} \] ### Step 3: Find the Coefficient of \(x^{32}\) To find the coefficient of \(x^{32}\), we set the exponent equal to 32: \[ 60 - 7r = 32 \] Solving for \(r\): \[ 7r = 60 - 32 \implies 7r = 28 \implies r = 4 \] Now, we find the coefficient corresponding to \(r = 4\): \[ \text{Coefficient of } x^{32} = \binom{15}{4} (-1)^4 = \binom{15}{4} \] ### Step 4: Find the Coefficient of \(x^{-17}\) Next, we find the coefficient of \(x^{-17}\): \[ 60 - 7r = -17 \] Solving for \(r\): \[ 7r = 60 + 17 \implies 7r = 77 \implies r = 11 \] Now, we find the coefficient corresponding to \(r = 11\): \[ \text{Coefficient of } x^{-17} = \binom{15}{11} (-1)^{11} = -\binom{15}{11} \] ### Step 5: Sum the Coefficients Now we sum the coefficients of \(x^{32}\) and \(x^{-17}\): \[ \text{Sum} = \binom{15}{4} - \binom{15}{11} \] Using the property of binomial coefficients \(\binom{n}{r} = \binom{n}{n-r}\): \[ \binom{15}{11} = \binom{15}{4} \] Thus, we have: \[ \text{Sum} = \binom{15}{4} - \binom{15}{4} = 0 \] ### Final Answer The sum of the coefficients of \(x^{32}\) and \(x^{-17}\) is: \[ \boxed{0} \]

To solve the problem of finding the sum of the coefficients of \(x^{32}\) and \(x^{-17}\) in the expansion of \((x^4 - \frac{1}{x^3})^{15}\), we will follow these steps: ### Step 1: Identify the General Term The general term in the binomial expansion of \((p + q)^n\) is given by: \[ T_{r+1} = \binom{n}{r} p^{n-r} q^r \] ...
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NAGEEN PRAKASHAN ENGLISH-BINOMIAL THEOREM-Exercise 8C
  1. Find the coefficient of x^(2).y^(7) in the expansion of (x+2y)^(9)

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  2. Prove that the ratio of the coefficient of x^10 in (1 - x^2)^10 & the ...

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  3. Prove that he coefficient of x^n in the expansion of (1+x)^(2n) is twi...

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  4. Find a positive value of m for which the coefficient of x^2 in the ex...

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  5. The sum of the coefficients of x^(32) and x^(-17) in (x^4- 1/(x^3))^15...

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  6. If the coefficient of x^(7)in [ax^(2) + (1/bx)]^(11) equals the coeffi...

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  7. about to only mathematics

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  8. Find the coefficient of x^(10) in the expansion of (1-x^(2))^(10)

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  9. about to only mathematics

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  10. Find the coefficient of x^(40) in the expansion of (1+2x+x^2)^(27)dot

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  11. If 'n' is a positive integer then prove that the coefficient fox^(m) i...

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  12. Find the term independent of x in ((3x^(2))/(2)-(1)/(3x))^(9)

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  13. Prove that the term independent of x in the expansin of (x+1/x)^(2n)i ...

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  14. Find the coefficient of a^5b^7in(a-2b)^(12)

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  15. Find the coefficient of x^(2).y^(7) in the expansion of (x+2y)^(9)

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  16. Prove that the ratio of the coefficient of x^10 in (1 - x^2)^10 & the ...

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  17. The coefficient of x^(n) in the expansion of (1 + x)^(2n) " and " (1 +...

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  18. Find a positive value of m for which the coefficient of x^(2) in the e...

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  19. Find the coefficients of x^(32)a n dx^(-7) in the expansion of (x^4-1/...

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  20. Find the coefficients of x^7 in (a x^2+1/(b x))^(11)a n dx^(-7)in(a x^...

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