How do you factor completely #12x^2-27#?

1 Answer
May 13, 2016

Answer:

#3(2x + 3)(2x - 3)#

Explanation:

In factoring - always look for a common factor first.

After taking out a common factor, the number of terms in the expressions is a huge clue as to what type of factorising it might be:

4 or more terms #rArr "grouping"#
3 terms #rArr " quadratic trinomial"#
2 terms #rArr "difference of two terms"#

#12x^2 - 27 = 3(4x^2 - 9)#

=#3(2x + 3)(2x - 3)#