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If the roots of the equation 4 x^2-(5 k+1) x+5 k=0 differ by unity, then which one of the following is a possible value of k ?

Options

  1. A-3
  2. B-1
  3. C- 1 5
  4. D- 3 5

Correct answer

C. - 1 5

Step-by-step solution

Let roots of 4 x^2-(5 k+1) x+5 k=0 are and . - =1( Given ), + = 5 k+1 4 , = 5 k 4 Now, ( - )^2=( + )^2-4 . aligned & 1= ( 5 k+1 4 )^2-4 5 k 4 & 25 k^2-70 k-15=0 & (k-3)(25 k+5)=0 & k=3, k=- 1 5 aligned

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