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If roots of equation `2x^(4) - 3x^(3) + 2x^2 - 7x -1 = 0` are `alpha, beta, gamma` and 5 then value of `sum(alpha+1)/alpha` is equal to:

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To solve the equation \(2x^4 - 3x^3 + 2x^2 - 7x - 1 = 0\) with roots \(\alpha, \beta, \gamma,\) and \(5\), we need to find the value of the expression \(\sum \frac{\alpha + 1}{\alpha}\). ### Step-by-step Solution: 1. **Understanding the Expression**: We need to evaluate: \[ \sum \frac{\alpha + 1}{\alpha} = \frac{\alpha + 1}{\alpha} + \frac{\beta + 1}{\beta} + \frac{\gamma + 1}{\gamma} + \frac{5 + 1}{5} \] This can be rewritten as: \[ = \left(1 + \frac{1}{\alpha}\right) + \left(1 + \frac{1}{\beta}\right) + \left(1 + \frac{1}{\gamma}\right) + \left(1 + \frac{1}{5}\right) \] 2. **Simplifying the Expression**: This simplifies to: \[ = 3 + \left(\frac{1}{\alpha} + \frac{1}{\beta} + \frac{1}{\gamma}\right) + \frac{6}{5} \] Thus, we have: \[ = 3 + \frac{1}{\alpha} + \frac{1}{\beta} + \frac{1}{\gamma} + \frac{6}{5} \] 3. **Using Vieta's Formulas**: According to Vieta's formulas for a polynomial \(ax^n + bx^{n-1} + cx^{n-2} + \ldots = 0\): - The sum of the roots \(\alpha + \beta + \gamma + 5 = -\frac{b}{a} = \frac{3}{2}\) - The sum of the products of the roots taken two at a time \(\alpha\beta + \alpha\gamma + \beta\gamma + 5(\alpha + \beta + \gamma) = \frac{c}{a} = 1\) - The product of the roots \(\alpha\beta\gamma \cdot 5 = -\frac{d}{a} = \frac{7}{2}\) 4. **Finding \(\frac{1}{\alpha} + \frac{1}{\beta} + \frac{1}{\gamma}\)**: We know: \[ \frac{1}{\alpha} + \frac{1}{\beta} + \frac{1}{\gamma} = \frac{\beta\gamma + \alpha\gamma + \alpha\beta}{\alpha\beta\gamma} \] From Vieta's, we can find: - \(\alpha + \beta + \gamma = \frac{3}{2} - 5 = -\frac{7}{2}\) - \(\alpha\beta + \alpha\gamma + \beta\gamma = 1 - 5(-\frac{7}{2}) = 1 + \frac{35}{2} = \frac{37}{2}\) - \(\alpha\beta\gamma = \frac{7}{10}\) 5. **Calculating the Final Value**: Thus: \[ \frac{1}{\alpha} + \frac{1}{\beta} + \frac{1}{\gamma} = \frac{\frac{37}{2}}{\frac{7}{10}} = \frac{37 \cdot 10}{2 \cdot 7} = \frac{370}{14} = \frac{185}{7} \] 6. **Putting it All Together**: Now substituting back: \[ = 3 + \frac{185}{7} + \frac{6}{5} \] To combine these, we need a common denominator. The least common multiple of \(7\) and \(5\) is \(35\): \[ 3 = \frac{105}{35}, \quad \frac{185}{7} = \frac{925}{35}, \quad \frac{6}{5} = \frac{42}{35} \] Thus: \[ = \frac{105 + 925 + 42}{35} = \frac{1072}{35} \] ### Final Answer: The value of \(\sum \frac{\alpha + 1}{\alpha}\) is \(\frac{1072}{35}\).
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RESONANCE-EQUATIONS -EXERCISE-1 (PART -1: PRE RMO)
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  2. x^2 + x + 1 is a factor of ax^(3) + bx^2 + cx + d = 0, then the real r...

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  3. If roots of equation 2x^(4) - 3x^(3) + 2x^2 - 7x -1 = 0 are alpha, bet...

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  4. If two roots of x ^(3) -ax ^(2) + bx -c =0 are equal in magnitude but ...

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  15. The value of root(3)(5+2sqrt(13)) + root(3)(5-2sqrt(13)) is= ……………..

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  16. If a, b, c, d satisfy the equation a + 7b + 3c + 5d = 0, 8a + 4b + 6c ...

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  18. If (x+1)^(2) =x, the value of 11x^(3) + 8x^(2) + 8x -2 is:

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  19. If one root of sqrt(a-x) + sqrt(b+x) = sqrt(a) + sqrt(b) is 2012, th...

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