Question

evaluate by using following suitable identity
999^3

Answer 1

999³= (1000 - 1)³

By using , (a-b)³ = a³ - b³ - 3ab (a - b)

= (1000)³ - (1)³ - 3(1000) (1) (1000 -1)

= 1000 000 0001 - 3000 x 999

= 1000 000 000 - 1-2997000

= 997002999