Given
36a² -24a +4
Find
the complete factorization
Solution
You can see that 4 is a factor of all terms, so you can rewrite the expression as
.... 4(9a² -6a +1)
The first and last terms in parentheses are squares, and the second term is double the product of their square roots, so the quantity in parentheses is a perfect square. Multiplying it out tells you this is a good guess. The minus sign tells you the repeated binomial factor will be a difference.
... = 4(3a -1)²
There is no further factorization.