FOIL method to solve a Quadratic- College Level

Factor the following quadratic equation using the FOIL method:

Answer:

Explanation:
The FOIL method is used when we have two linear equations (otherwise referred to here as factors) and we combine them to obtain a quadratic equation. The Term FOIL stands for the following:
F irst term
O uter term
I nner term
L ast term
The standard form of a quadratic equation is:

In the above equation the a term is 1, the b term is 10 and the c term is 21. In order to factor using FOIL, we will need to come up with two terms whose sum equals the b terms and whose product equals the c term. Since both terms are positive, we don’t need to worry about signs for this problem.
Upon examining the problem we determine that the numbers 7 and 3 work since their sum equals 10 and their product equals 21. We now have our answer as:

If we multiply the above factors using the FOIL method we will obtain the equation we started with.
For additional information about various factoring techniques go to: Introduction to Quadratic Functions.

©Copyright 2007.Najwa S. Hirn. All rights reserved.