SOLUTION: 3x^3+2x^2+x-6 is x-1 explain why you can eliminate 3x^2-5x-6 and 3x^3+x^2-3

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: 3x^3+2x^2+x-6 is x-1 explain why you can eliminate 3x^2-5x-6 and 3x^3+x^2-3      Log On


   

Question 406075: 3x^3+2x^2+x-6 is x-1
explain why you can eliminate 3x^2-5x-6 and 3x^3+x^2-3
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi,

 x = 1 is a real root. Dividing by (x-1) to find the other two roots:

      3x^2 + 5x +6

      _______________________

x -1 | 3x^3+2x^2+x-6



(x-1)(3x^2 + 5x +6)= 0

     (3x^2 + 5x +6)= 0

x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

x+=+%28-5+%2B-+sqrt%28-47+%29%29%2F%286%29+

x+=+%28-5+%2B-+i%2Asqrt%2847+%29%29%2F%286%29+

the remaining two roots of 3x^3+2x^2+x-6 are complex roots.