Answer
$(a+3)(5a^2+31a+46)$
Work Step by Step
The factor $(a+3)$ is common to both terms.
Factor out $a+3$ to obtain:
$=(a+3)[5(a+3)^2-2+(a+3)]
\\=(a+3)[5(a+3)^2-2+a+3]
\\=(a+3)[5(a+3)^2+a+1]$
Square the binomial to obtain:
$\\=(a+3)[5(a^2+6a+9)^2+a+1]$
Distribute $5$ to obtain:
$\\=(a+3)(5a^2+30a+45+a+1)
\\=(a+3)(5a^2+31a+46)$
