You Will Need
 A polynomial
 A pencil
 Paper
Steps

Step 1
Find the greatest common factor
Look at the expression and find the greatest common factor for each term. For the expression 2x2 + 4x, both terms contain factors of 2 and factors of x.

Step 2
Factor out greatest common factor
Remove the largest factors common shared by each term – 2 and x – and place them outside a set of empty parentheses.

Step 3
Determine what GCF is multiplied with
Determine the greatest common factor of each term of the expression. In the example, it's 2x. Then, determine what it is multiplied with to equal the original two terms and place those terms inside the parentheses. 2x times x equals 2x2, and 2x times 2 equals 4x.

Step 4
Find the difference of squares
Finding the difference of two squares is another type of factoring. In the expression x2 – 4, x2 is the square of x and 4 is the square of 2.

Step 5
Make parentheses
To factor the difference of two squares, draw two sets of parentheses. On the left side of each set of parentheses, split the first square, x2, into two x's.

Step 6
Split second square
Write the second square in the right side of the parentheses. Since the second term is being subtracted, each set of parentheses must have a different sign.