# Algebra 1 : Factoring Polynomials

## Example Questions

### Example Question #331 : Polynomials

Factor the following expression.

Explanation:

The factored form of this equation should be in the format .

To yield the first term in our original equation (),  and .

To yield the last term in our original equation (), we can set  and .

We can check our answer by using FOIL to expand back to the original expression.

### Example Question #21 : How To Factor A Polynomial

Factor the following expression.

Explanation:

The factored form of this equation should have the format .

To yield the first term in our original equation (),  and .

To yield the final term in our original equation (), we can set  and .

If you are unsure of your answer, you can check using FOIL to end up with the original equation.

### Example Question #22 : How To Factor A Polynomial

Factor the following expression.

Explanation:

To factor an expression like this, we can use factoring by grouping. The greatest common factor in the first two terms is , so should be factored out.

Now, look at the last two terms. The greatest common factor in these terms is . Factor out the .

Now, both terms in parentheses are . We can group and together, and multiply it by .

We can check the answer using FOIL to end up with the original expression.

### Example Question #5 : Solving By Factoring

Factor the following expression.

Explanation:

This expression involves the difference of two cubic terms. To factor an expression in this format, we can use a special formula.

Before we can use this formula, we need to manipulate our original expression to identify and .

Comparing this with the formula,  and . Now we can use the formula to factor.

### Example Question #341 : Polynomials

Factor completely:

Explanation:

can be factored out of each term, so do this first:

is the sum of squares and cannot be factored, so  is the correct factorization.

### Example Question #21 : Factoring Polynomials

Factor completely:

Explanation:

can be factored out of each term, so do this first:

The second factor can be factored as the difference of two squares:

### Example Question #21 : How To Factor A Polynomial

Factor completely:

The polynomial is prime.

Explanation:

This is a difference of squares and can therefore be factored using the appropriate pattern:

### Example Question #22 : Factoring Polynomials

Factor the following polynomial:

Explanation:

The coefficients are 20, 5, and 10. The greatest common factor of those three numbers is 5. Factor out the 5, making sure to keep the signs the same inside the parentheses:

Now factor out the  term:

### Example Question #21 : Factoring Polynomials

Factor by grouping.

Not factorable

Explanation:

Looking at the first two terms, the greatest common factor is 3b, hus we can factor out 3b.

Looking at the last two terms, the greatest common factor is –1. Factor out the –1.

Notice that you can factor out the .

### Example Question #1 : Solving By Factoring

Factor the following expression.

Not factorable