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

The first step expands (a + b)(a² − ab + b²) by multiplying each term in the first factor by each term in the second. This is the distributive property, producing a³ − a²b + ab² + a²b − ab² + b³. Therefore, the correct choice is A, distributive property.

AI-written and checked against the verified answer.