Answer
$(x+1)(3x+5)$
Work Step by Step
$3x^{2}+8x+5=$
... ... Searching for two factors of $ac=15$ whose sum is $b=+8,$
we find$\qquad+5$ and $+3.$
Rewrite the middle term and factor in pairs:
=$3x^{2}+3x+5x+5=$
$=3x(x+1)+5(x+1)$
= $(x+1)(3x+5)$
