Hey Guys, So I'm currently factoring polynomials. As you all know,when trying to factor a polynomial with 4 terms,the answer can be the difference of a trinomial and monomial squares. So I had the problem 4a^2-4ab+b^2-c^2 I thought(book doesn't explain it well) that your first step was to group like terms to create your trinomial which we then end up with: (4a^2-4ab+b^2)-c^2 From there we solve and get: (2a-b)^2-c^2 Thus being solved: =(2a-b-c)(2a-b+c) Which is the correct answer. But then they had this problem: a^2+b^2-c^2-2ab My logic behind grouping like terms then falls short in this one,in which I now assume we just randomly select 3 terms to isolate. This is where things start getting sticky... The correct answer is (a-b+c)(a-b-c) But I can't seem to find my order of operations... I find that I group (a^2-b^2+c^2)-2ab But that's as far as I get... Any insight? Thanks in advance.