We conclude that 'None of the above' is the correct answer.
Step-by-step explanation:
Given the expression
![7x^2\:-\:12x\:-\:4](/tpl/images/0901/4684/29096.png)
Breaking the expression into groups
![7x^2\:-\:12x\:-\:4=\left(7x^2+2x\right)+\left(-14x-4\right)](/tpl/images/0901/4684/d1219.png)
Factor out
from ![7x^2\:+\:2x](/tpl/images/0901/4684/4dddf.png)
![=x\left(7x+2\right)](/tpl/images/0901/4684/4d43a.png)
Factor out -2 from ![\left(-14x-4\right)](/tpl/images/0901/4684/65c55.png)
![=-2\left(7x+2\right)](/tpl/images/0901/4684/3f804.png)
so the expression becomes
![7x^2\:-\:12x\:-\:4=\left(7x^2+2x\right)+\left(-14x-4\right)](/tpl/images/0901/4684/d1219.png)
![=x\left(7x+2\right)-2\left(7x+2\right)](/tpl/images/0901/4684/7a29b.png)
Factor out the common term ![7x+2](/tpl/images/0901/4684/97791.png)
![=\left(7x+2\right)\left(x-2\right)](/tpl/images/0901/4684/28ffe.png)
Therefore, from the given options, we conclude that 'None of the above' is the correct answer.