Question

What is the form of the Difference of Cubes identity?

Answer 1

The answer is D. I hope this is right.

Answer 2

Solution:

The difference of cubes identity is

if a and b are any two real numbers, then difference of their cubes , when taken individually:

→a³ - b³= (a-b)(a² + a b + b²)→→→Option (D) is true option.

I will show you , how this identity is valid.

Taking R H S

(a-b)(a² +b²+ab)

= a (a² +b²+ab)-b(a² +b²+ab)

= a³ + a b² +a²b -b a² -b³ -ab²

Cancelling  like terms , we get

= a³ - b³

= L H S