
Answer:
Step-by-step explanation:
The factoring of the sum of cubes is ...
 a³ +b³ = (a +b)(a² -ab +b²)
1. a=2x, b=1
 = (2x)³ + 1³
__
2. There is an overall factor of 2x. Once that is factored out, a=x, b=2.
 = (2x)(x³ +2³)
__
3. a=x, b=2
 = x³ +2³