Editing Factorization (section)

====Grouping====
Grouping terms may allow using other methods for getting a factorization.

For example, to factor 
<math display="block">4x^2 + 20x + 3xy + 15y, </math>
one may remark that the first two terms have a common factor {{mvar|x}}, and the last two terms have the common factor {{mvar|y}}. Thus
<math display="block">4x^2+20x+3xy+15y = (4x^2+20x) + (3xy+15y) = 4x(x+5) + 3y(x+5). </math>
Then a simple inspection shows the common factor {{math|''x'' + 5}}, leading to the factorization 
<math display="block">4x^2+20x+3xy+15y = (4x+3y) (x+5).</math>

In general, this works for sums of 4 terms that have been obtained as the product of two [[binomial (polynomial)|binomials]]. Although not frequently, this may work also for more complicated examples.