How do you factor a quadrinomial?

Answer 1

You look for common letters (variables) or numbers which can be divided by a common factor. Example : To factor 2xy + 8xyz + 6yz + 4y, you can notice that every number divides by 2 and that every term contains a y. So you take out 2 and y in front of a set of parentheses, and you remove a 2 and a y from every term : 2y ( x + 4xz + 3z + 2 ). If you mean a quadrinomal in the sense of a trinomial with an extra x-cube term, for example x^3 + 2 x^2 + 8 x + 5 = 0, then you need the equivalent of the quadratic formula for cubic equations. It does exist but it's not well known, and it involves complex numbers. Nasty stuff. ^_^