Question

Evaluvate 999 cube using suitable identity

Answer 1

997002999 is the cube—————hit———

Answer 2

999 can be written as (1000-1) so

999³ is (1000-1)³

by identity (a-b)³

we can say

(999)³=(1000-1)[(1000)²-2(1000)(1)+(1)²]

999[1000000-2000+1]

999[9998001]