How do you factor quadratic equations box method?
Here's an example:
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:
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
We'll write those factors on a new first row and a new left column:
The factors are the top row and the left column:
Using a different box
If we had put the
The factors are