Example 3:  Expand:  (3x – 2)(3x + 2)

Solution:

 

This example illustrates that a difference of two terms times the sum of the same two terms results in the difference of the squares of those two terms.  In general, the following binomial products should be recognized as the outer and inner terms cancel:

(a – b)(a + b) = a² – b²

(a + b)(a – b) = a² – b²

toc | return to top | previous page | next page