Factor by grouping.
-$20 x ^ { 2 } - 15 x - 16 x + 12$
A) $( 5 x - 4 ) ( 4 x - 3 )$
B) $( 20 x + 4 ) ( x + 3 )$
C) $( 20 x - 4 ) ( x - 3 )$
D) $( 5 x + 4 ) ( 4 x + 3 )$

Question

Quizplus · Accepted Answer

We can group the first two terms and the last two terms: 
$$(20x^2 - 15x) - (16x - 12)$$
From the first group we can factor out 5x and from the second group we can factor out -4, giving us:
$$5x(4x-3) - 4(4x-3)$$
We can now see that both terms have a common factor of (4x-3), so we can factor that out as well:
$$(4x-3)(5x-4)$$
which is the same as answer choice A.

Factor by Grouping 20x2−15x−16x+1220 x ^ { 2 } - 15 x - 16 x + 1220x2−15x−16x+12

Factor by Grouping $20 x ^ { 2 } - 15 x - 16 x + 12$