solving un-nice quadratics

several U.S. blogs (James Tanton in particular) advocate multiplying by 4 in order to more easily complete the square when the x-coefficient is an odd number:

which seems a helpful technique

my preference, as mentioned previously, is to transform the equation using a difference of two squares technique (as advocated by David Wells):

this preference is because it's straightforward
and also because I quite like students to be able to mentally square something.5