Factorise `x^2-23 x^2+142 x-120` .

Explanation

Here, `P(x) = x^3-23x^2+142x-120`

Factors of constant term `120` are

`+-1,+-2,+-3,+-4,+-5,+-6,+-8,+-10,+-12,+-15,+-20,+-24,+-30,+-40,+-60,+-120`

`P(1) = 1-23+142-120 = 0`

From Factor theoram,

`(y-a)` is a factor of `P(y) if P(a) = 0`

Here, as `P(1)` is `0`, so, `(x-1)` is a factor of `P(x)`.

If, we divide `P(x)` by `(x-1)`, we get, `x^2-22x+120`.
Please refer video for the division.
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