# How do you factor quadratic equations box method?

##### 1 Answer

Here's an example:

Example: Factor

You have

Multiply

Fins two numbers whose product is

and whose sum is

Because we want the product to be negative, one number is positive and the other is negative. Because we want the sum to be positive, the positive factor is the one with the greater absolute value.

We start the list:

**STOP** **the sum is**

Write

(Or by

The **"factoring box"** is a way of doing the factoring by grouping.

To use this box, you must first take out any factor that is common to all 3 terms. (If we had started with

Put the first and last terms in main diagonal (upper left and lower right) Then put in the two terms we found above

Notice that each row has common factors and each column has common factors (in some problems the only common factor is

and

We'll write those factors on a new first row and a new left column:

(The

The factors are the top row and the left column:

**Using a different box**

If we had put the

The factors are