Question 724453
{{{x^2+49}}}....write {{{49}}} as {{{7^2}}}

{{{x^2+7^2}}}...here we have the sum of squares; usually when you factor, you are looking for real factors, but if you allow 
complex factors then you can always factor {{{A^2+B^2}}} like this:

{{{A^2+B^2 = A^2-(-1*B^2) = A^2-(iB)^2 = (A+iB) (A-iB)}}}


so, you will have 

{{{x^2-(7i)^2}}} which is

{{{(x-7i)(x+7i)}}}