- The Difference of Two Squares
- Fundamental Rules of Factoring
- Perfect Square Trinomials
Inside Collection (Textbook): Basic Mathematics Review
Summary: This module is from Elementary Algebra by Denny Burzynski and Wade Ellis, Jr. Factoring is an essential skill for success in algebra and higher level mathematics courses. Therefore, we have taken great care in developing the student's understanding of the factorization process. The technique is consistently illustrated by displaying an empty set of parentheses and describing the thought process used to discover the terms that are to be placed inside the parentheses. The factoring scheme for special products is presented with both verbal and symbolic descriptions, since not all students can interpret symbolic descriptions alone. Two techniques, the standard "trial and error" method, and the "collect and discard" method (a method similar to the "ac" method), are presented for factoring trinomials with leading coefficients different from 1. Objectives of this module: know the fundamental rules of factoring, be able to factor the difference of two squares and perfect square trinomials.
Recall that when we multiplied together the two binomials
Notice that the terms
Since we know that
Factor
We can check our factorization simply by multiplying.
We can check our factorization by multiplying.
Now we see that
Be careful not to drop the factor 3.
If possible, factor the following binomials completely.
There are two fundamental rules that we follow when factoring:
Factor each binomial completely.
Now we can see a difference of two squares, whereas in the original polynomial we could not. We’ll complete our factorization by factoring the difference of two squares.
Finally, the factorization is complete.
These types of products appear from time to time, so be aware that you may have to factor more than once.
Factor each binomial completely.
Recall the process of squaring a binomial.
| Our Method Is | We Notice |
| Square the first term. | The first term of the product should be a perfect square. |
| Take the product of the two terms and double it. | The middle term of the product should be divisible by 2 (since it’s multiplied by 2). |
| Square the last term. | The last term of the product should be a perfect square. |
Perfect square trinomials always factor as the square of a binomial.
To recognize a perfect square trinomial, look for the following features:
In other words, factoring a perfect square trinomial amounts to finding the terms that, when squared, produce the first and last terms of the trinomial, and substituting into one of the formula
Factor each perfect square trinomial.
The terms that when squared produce
The middle term is divisible by 2, and
The middle term
Thus,
Factor, if possible, the following trinomials.
not possible
For the following problems, factor the binomials.
For the following problems, factor, if possible, the trinomials.
not factorable
((Reference)) Factor
((Reference)) Factor
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