Question

evaluate the following using suitable identity (998) cube​

Answer 1

answer :994011992

998 can be written as (1000 – 2)

∴ 998 = 1000 – 2

(998)3 = (1000 – 2)3

We know the formula

(a – b)3 = a3 – b3 – 3ab(a – b)

(1000 – 2)3 = (1000)3 – (2)3 – 3 × 1000 × 2(1000 – 2)

(998)3 = 1000000000 − 8 – 5988000

(998)3 = 994011992

hope it will help you