Question

evalute using identity
(999)to power 3

Answer 1

this is nothing but (1000-1)^3
(a-b)^3 = a^3 -3ab(a-b)-b^3
(1000-1)^3 = 1000^3 -3*1000*1(1000-1)-1^3
                = 1000000000-3000*999-1
                = 997002999
                     

Answer 2

Q. (1000-1)³
= 1000³ -3×1000²×1+3×1000×1²+1³
= 1000000000-3000000+3000+1
= 997002999