Problem Solving (PS) | Re: For which of the following values of k will (k + 10)x^2 + (k + 10)x 9

For the roots to be equal, the determinant should be zero. For a quadratic equation represented in the form \(ax^2 + bx + c \), the determinant is given by\( b^2 - 4ac\).

For the given equation, the determinant is \((k + 10)^2 - [4 (k+10) * (-9)]\)

\((k + 10)^2 +36 (k+10) = 0\)

\((k + 10)( k + 10 +36 ) = 0\)

\((k + 10)( k + 46 ) = 0\)

The value of k cannot be -10, as the quadratic equation will not hold true for k = -10.

Hence, k = -46

Option A

Statistics : Posted by gmatophobia • on 20 Sep 2023, 04:30 • Replies 1 • Views 110

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