How would 3x^2-27y^2 be factored completely?

Answer 1

isnt it the difference of two squares?

3(x^2-9y^2)=3(x-3y)*(x+3y)

Answer 2

Yes but isnt the difference of two squares just one technique to factor polynomials?

Answer 3

Of course. If one technique works to factor a polynomial, it is factored.