Question
Prove by factor theorem that
$(x - 3)$ is a factor of $5x^2 - 21 x +18$
$(x - 3)$ is a factor of $5x^2 - 21 x +18$
✓
Answer
$x - 3 = 0 \Rightarrow x = 3$
Substituting this value , we get
$f(3) = 5(3)^2 - 21(3) + 18$
$= 45 - 63 + 18$
$= 0$
Substituting this value , we get
$f(3) = 5(3)^2 - 21(3) + 18$
$= 45 - 63 + 18$
$= 0$
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