Answer:
Second option
![( - 7x + 4)( - 7x - 4)](https://img.qammunity.org/2020/formulas/mathematics/high-school/5sh8sg90ys9kljkfif34mplyc08whmlm1h.png)
Explanation:
If you multiply it out you get:
![49 {x}^(2) + ( - 7x * - 4) + ( - 7x * 4)- 16](https://img.qammunity.org/2020/formulas/mathematics/high-school/61py1h0ucpgwceoui7m7s8zccgq3a6xg8p.png)
The two middle terms cancel out because of the sign difference of the two fours.
Result:
![49 {x}^(2) - 16](https://img.qammunity.org/2020/formulas/mathematics/high-school/ba0dhpquoes41kpalfmto9uf6x7yiupvj5.png)
Difference of squares. If the two multiplied brackets look exactly the same except for a sign difference in one of the terms (4 in this case) it is difference of squares.