3X2 - 12
3(X2 - 4)
=========All the factoring that can be done here.
-2x3 - 10x2 - 12x = -2x*(x2 + 5x + 6) = -2x*(x + 2)*(x + 3)
For a start, you can look for a common factor, and separate it. What remains (the other factor) will only be a polynomial of degree 2; I assume you already learned how to factor that.
x(x - 2)(7x + 2)
3(3x + 2)(3x - 2)
(2x + 1)(x - 4)
-2x(x + 3)(x + 2)
2x(x + 1)(x - 6)
3x^3(x - 4)
(3x - 8)(8x + 5)
(2x - 3)(3x + 2)
(3x - 4)(2x^2 + 6x + 5)
If that's -5, the answer is (x - 1)(3x + 5) If that's +5, it gets ugly in a hurry.
6y2+17y-14 = (2x+7)(3x-2) when factored
3x squared minus 25x minus 28
x(3x - 2)
3x(6x - 1)
(x-3)(3x+1)
(3x + 8)(3x - 8)
(3x + 1)(x - 5)
It is: (3x+4)(2x-3) when factored
(x + 3)(3x - 2)
3x2-x-2 = (3x+2)(x-1)
(x + 2)(3x - 1)(3x + 1)
It is: (2x+3)(3x-8) when factored
3x^2 -14x +15 = (3x-5)(x-3)