Factorise `x^3-23 x^2+142 x-120`

Explanation

`=>x^3−x^2−22x^2+22x+120x−120`
`=>x^3−x^2−22x^2+22x+120x−120`
`=x^2(x−1)−22x(x−1)+120(x−1)`
`=>(x−1)(x^2−22x+120)`
`=>(x−1)(x^2−10x−12x+120)`
`=>(x−1){x(x−10)−12(x−10)}`
`=>x^2(x−1)−22x(x−1)+120(x−1)`
`=>(x−1)(x^2−22x+120)`
`(x−1)(x^2−10x−12x+120)`
`=>(x−1)(x−10)(x−12)`