Question

factorise : a3 - a - 120

Answer 1

First we need to find numbers which makes the equation =0
By Hit and Trial method we get 5 as such number
So (a-5) is a factor of a^3 - a -120
By dividing$a^3 -a-120$ by a-5
We get $a^2 + 5a+120$
So The factorization of a³ - a-120
is (a-5)(a² + 5a+24)

Answer 2

Step-by-step explanation:

a^3 - a - 120

(a^3 - 125) - (a-5) = (a^3 -125) - (a-5)

(a-5) (a^2 + 5a + 25) - (a-5) = (a-5) (a^2 + 5a + 25) - (a-5)

(a-5) (a^2 + 5a + 24)