Which of the following expressions is equivalent to a3 + b3?
(a - b)(a2 + ab + b2)
a3 + a2b + ab2 - a2b - ab2 - b3
(a + b)(a2 - ab + b2 )
(a + b)(a3 + b3)
~all the big numbers next to the variables are the exponent example, b2 ; b^2

ANSWER


EXPLANATION

To find the expression that is equivalent to

we must first expand

Then we rearrange to find the required expression.

So let's get started.



We expand the parenthesis on the right hand side to get,



We expand again to obtain,



Let us group the cubed terms on the right hand side to get,





We make the cubed terms the subject,



We factor to get,



We expand the bracket on the left hand side to get,



We finally simplify to get,