How do you find all the zeros of $f(x) = x^3 – 9x^2 + 20x$ with its multiplicities?

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Answer 1 · 2016-08-19T23:09:26

$f(x)$ has zeros $0, 4, 5$

Note that $4+5=9$ and $4*5=20$

So we find:

$f(x) = x^3-9x^2+20x = x(x-4)(x-5)$

Hence zeros: $0, 4, 5$

How do you find all the zeros of f(x) = x^3 – 9x^2 + 20xf(x) = x^3 – 9x^2 + 20x with its multiplicities?