Question

how do you factor 3x^3-6x^2-24x

I know that it becomes 3x(x^2-2x-8), but you can still factor it more. how?

Answer 1

Try distributing. I'm pretty sure that 3x times x^2 would be 3x^3, because you add the exponents. You'd do it with the rest of the stuff in the parentheses, too. :)

Answer 2

after you get 3x(x^2-2x-8), look at what is in the parenthesis.
x^2-2x-8
what are 2 numbers that add to the constant, 8?
at the same time, these 2 numbers must equal -2
the two numbers should be -4 and 2
so the final answer would be..
3x(x-4)(x+2)
hope this helps. =)