Question

How do you factor `(x^2-4x^2-9x+36`?

Answer 1

`f(x) = -3x^2 - 9x + 36) = -3(x^2 + 3x - 12)`

The trinomial in parentheses has D = 9 + 48 = 57. It is not a perfect square, then this trinomial can't be factored.