How do you factor by grouping with three terms $252v + 48v ^2 -12v ^3$ ?

Question

1525 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-04-30T15:32:21

First simplify by extracting the obvious factor of $12v$
$252v+ 48v^2-12v^3$
$=12v(21+4v-v^2)$
or
$=(-12v)(v^2-4v-21)$

$21$ can be factored as $3xx7$
and the difference between 3 and 7 is 4

so
$= (-12v)(v^2+3v-7v-21)$

$=(-12v)(v(v+3) - 7(v+3))$

$=(-12v)(v-7)(v+3)$

How do you factor by grouping with three terms 252v + 48v ^2 -12v ^3252v + 48v ^2 -12v ^3?