Answer:
-4(3c + 4)(c + 1)
Explanation:
Reorder the expression
-12c² - 28c - 16
Divide it by -4
3c² + 7c + 4
Factor it by multiplying a (3) and c (4), then finding 2 factors that add up to b (7)
Two factors of 12 that add up to 7 are 4 and 3.
Use 4c and 3c to substitute for 7c in the expression, and simplify
3c² + 7c + 4
3c² + 3c + 4c + 4
3c(c + 1) + 4(c + 1)
(3c + 4)(c + 1)
Since we factored out a -4 in the beginning, add this in front
-4(3c + 4)(c + 1)