Answer
$2x^{4}(3x+2) +4x^{2}(3x+2) + 3(3x+2)$
Work Step by Step
a) $6x^{5} + 4x^{4} + 12x^{3} + 8x^{2} + 9x + 6$
Group the first two terms, middle two terms and last two terms together
$(6x^{5} + 4x^{4}) + (12x^{3} + 8x^{2}) + (9x + 6)$
Factor out the GCF from the first two terms, middle two terms and last two terms
$2x^{4}(3x+2) +4x^{2}(3x+2) + 3(3x+2)$