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Question
Choose the correct answer for the following question.
One of the roots of equation x2 + mx – 5 = 0 is 2; find m.
Options
-2
`-1/2`
`1/2`
2
Solution
For the equation, x2 + mx – 5 = 0
one of the roots is 2. So, 2 should satisfy the given equation.
\[\left( 2 \right)^2 + m \times \left( 2 \right) - 5 = 0\]
\[ \Rightarrow 4 + 2m - 5 = 0\]
\[ \Rightarrow 2m - 1 = 0\]
\[ \Rightarrow m = \frac{1}{2}\]
Hence, the correct answer is `1/2`.
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