Answer
$6(3v^{2}+4)(2v-7)$
Work Step by Step
$36v^{3}=2.2.3.3.v.v.v$ and $126v^{2}=$$2.3.3.7.v.v$
Hence, $GCF=$$2.3.3.v.v=18v^{2}$
$48v=2.2.2.2.3.v$ and $168=2.2.2.3.7$
Hence, $GCF=$$2.2.2.3=24$
After grouping:
$=(36v^{3}-126v^{2})+(48v-168)$
$=18v^{2}(2v-7)+24(2v-7)$
$=(18v^{2}+24)(2v-7)$
$=6(3v^{2}+4)(2v-7)$