Answer
$(2a-1)(4a^2+2a+1)$
Work Step by Step
RECALL:
$A^3-B^3=(A-B)(A^2+AB+B^2)$
The given binomial can be written as:
$=2^3a^3-1^3
\\=(2a)^3-1^3$
The binomial above is a difference of two cubes.
Factor using the the formula above with $A=2a$ and $B=1$ to obtain:
$=(2a-1)[(2a)^2+(2a)(1) + 1^2)
\\=(2a-1)(4a^2+2a+1)$
