x^3+6x-27
How would i factor that? I believe i start out with (x-3)(x^2 but i dont know where to go from that? Please help.
2006-09-17 16:45:03 · 3 answers · asked by mryabin 2 in Science & Mathematics ➔ Mathematics
It cant be (x-3)(x+9) because then you get x^2, the problem is with an x^3 in it. If you make it (x-3)(x^2+9) then you end up with an x^2 in the answer too, and i dont want that. Any ideas? Please...
2006-09-17 17:25:10 · update #1
If you start with (x - 3) (x^2 + ??) it gives you a -3x^2, which as you say you don't want, so you have to cancel it by continuing with (x - 3) (x^2 + 3x + ??). It would be similar if you had been trying to factor x^3 + x^2 + ... and decided to try (x - 3) (x^2 + ??); you can see it giving you -3x^2, so to get the x^2 term correct you continue with (x - 3) (x^2 + 4x + ??).
This is called "synthetic division", and it only comes out correctly at the end if you have started with a correct divisor. Your starting expression is not zero for x = 3, so (x - 3) as a divisor doesn't work. Worse, your starting expression is not zero for ANY integer value of x, so there is no simple (x - a) or (x + a) divisor which works. Maybe there is a misprint.
2006-09-18 00:07:44 · answer #1 · answered by Anonymous · 0⤊ 0⤋
(x-3)(x+9)
2006-09-18 00:23:16 · answer #2 · answered by iyiogrenci 6 · 0⤊ 1⤋
Well, it's like this. Do you know how Helena Rubinstein became pregnant? Elementary, dear student. Max Factor.
2006-09-18 00:04:21 · answer #3 · answered by Anonymous · 0⤊ 1⤋