Question 257078
First, lets rearrange the terms as
{{{(a^2 -2ab + b^2)}}} +{{{(3b - 3a + 4)}}}
The left side is just a perfect square trinomial and is factored as
{{{(a-b)^2}}}
the right side has a common factor of 3 for two terms and can be factored as
{{{-3(a-b) + 4}}}
putting these back together, we get
{{{(a-b)^2 -3(a-b) + 4}}}
Now we have general factoring as
{{{(a-b -4)(a-b + 1)}}}