Final answer:
The common factoring technique used for polynomials is Factoring by Grouping, which involves rearranging terms into smaller groups that can be factored separately. Factoring by Difference of Squares is also a widespread method for factoring quadratic equations.
Step-by-step explanation:
The factoring technique commonly used to factor polynomials is A) Factoring by Grouping. This method involves rearranging the terms of the polynomial and factoring them in smaller groups which then can be combined to achieve the factored form of the original polynomial. Another common method, particularly for quadratic equations, which are second-order polynomials, is B) Factoring by Difference of Squares. This method is used when a polynomial can be expressed as a square of one expression subtracted from the square of another expression.
The other options provided are not primarily factoring techniques. C) Factoring by Quadratic Formula is a method for solving quadratic equations, not for factoring them. Lastly, D) Factoring by Long Division is actually a process to divide one polynomial by another, which could lead to factoring but is not a primary factoring technique itself.