The answer is: (x-3)(x-1)(x+2)
Because the first term is x^3, it means that there must be 3 independent x's multiplying by each other. From there you just have to est what numbers to pair them with. If that doesn't make sense let me explain more:If you have x^2 it will be:(x + y) (x + z) If you have x^3 it will be: (x + y) (x + z) (x + g) If you have x^4 it will be: (x + y) (x + z) (x + g) (x + f) etc; now all you have to do after you pick which one it matches with, it just find what the value of y, z, and g are through trial and error. I am not showing all my trial and error because it is long to type out, easier to just explain the process.