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Question
If 2x + 1 is a factor of 2x2 + ax – 3, find the value of a.
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Solution
2x + 1 is a factor of f(x) = 2x2 + ax – 3.
∴ `f((-1)/2) = 0`
`\implies 2((-1)/2)^2 + a((-1)/2) - 3 = 0`
`\implies 1/2 - a/2 = 3`
`\implies` 1 – a = 6
`\implies` a = –5
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