# Factoring by Grouping (Part 2)

How to factor polynomials by grouping and using other formulas together: examples and their solutions.

## Example 1

Polynomials that cannot be factored by using formulas

can mostly be solved by grouping.

Factoring by grouping (part 1)

Split the polynomial into two parts.

Factor the first two terms:*x*(*y*^{2} - *z*^{2}).

The next two terms are already set:

(*y*^{2} - *z*^{2}).

Factor the polynomial by using the common factor:

(*y*^{2} - *z*^{2}).

Factor the available factors thoroughly.*y*^{2} - *z*^{2} = (*y* + *z*)(*y* - *z*)

Factoring the difference of squares

## Example 2

Split the polynomial into two parts.

Factor the first three terms:*a*(*a*^{2} + 2*a* - 3).

Factor the next three terms

with making (*a*^{2} + 2*a* - 3):

-2*b*(*a*^{2} + 2*a* - 3).

Factor the polynomial by using the common factor:

(*a*^{2} + 2*a* - 3).

Factor the available factors thoroughly.*a*^{2} + 2*a* - 3 = (*a* + 3)(*a* - 1)

Factoring a quadratic trinomial