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Question
x – 1 is a factor of 8x2 – 7x + m; the value of m is ______.
Options
–1
1
–2
2
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Solution
x – 1 is a factor of 8x2 – 7x + m; the value of m is –1.
Explanation:
We know that,
If x – a is a factor of f(x)
Then f(a) = 0
Let f(x) = 8x2 – 7x + m
Since x – 1 is a factor of f(x)
Then f(1) = 0
`\implies` 8 × 12 – 7 × 1 + m = 0
`\implies` 8 – 7 + m = 0
`\implies` 1 + m = 0
`\implies` m = –1
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