Question

What is the justification for the first step in proving the formula for factoring the sum of cubes?

a3 + b3 = (a + b)(a2 – ab + b2)

= a3 – a2b + ab2 + a2b – ab2 + b3

Answer 1

Explanation:

One approach would be to begin the indicated multiplication: Multiply a² by a, obtaining a³, which is the first term of the product a3 – a2b + ab2 + a2b – ab2 + b3. Please use " ^ " to indicate exponentiation, or (²) or (³):

a(a² - ab + b²) = a³ (plus 2 more terms, which are -a²b and ab²).

Here we are applying the distributive property of multiplication.

Answer 2

the answer is a

Explanation: