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Question
Prove by factor theorem that
(x - 3) is a factor of 5x2 - 21 x +18
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Solution
x - 3 = 0 ⇒ x = 3
Substituting this value , we get
f(3) = 5(3)2 - 21(3) + 18
= 45 - 63 + 18
= 0
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