First, we have to factorize by common factors
[tex]\begin{gathered} 7x^4+14x^3\text{ - }168x^2 \\ 7x^2(x^2+2x\text{ -}24) \end{gathered}[/tex]
So, until this point we have this Now let's factorize the polynomial inside the parenthesis
[tex]7x^2(x+6)(x\text{ - }4)[/tex]
That would be the final expression. Option A is correct
