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Question
Determine the value of m, if (x + 3) is a factor of x3 – 3x2 – mx + 24
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Solution
p(x) = x3 – 3x2 – mx + 24
when x + 3 is a factor
P(–3) = 0
(–3)3 – 3(–3)2 – m(–3) + 24 = 0
– 27 – 27 + 3m + 24 = 0
– 54 + 24 + 3m = 0
– 30 + 3m = 0
3m = 30
m = `30/3`
= 10
The value of m = 10
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