SOLUTION: a partial solution set is given for each equation. Find complete solution set: x^3 + 3x^2 - 13x -15 =0 {-1} i keep getting 1 -2 -13 and -4 as the ansers for each when i subract

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: a partial solution set is given for each equation. Find complete solution set: x^3 + 3x^2 - 13x -15 =0 {-1} i keep getting 1 -2 -13 and -4 as the ansers for each when i subract      Log On


   



Question 534316: a partial solution set is given for each equation. Find complete solution set:
x^3 + 3x^2 - 13x -15 =0 {-1}
i keep getting 1 -2 -13 and -4 as the ansers for each when i subract. What am i doing wrong??
the answer is {-1,-5,3} and im not even close
HOw do i show my work with out graphing. the teacher doesnt want us to graph it.

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
you're given one root and you need to find the other two (the equation is 3rd degree)

-1 is a root, so x+1 is a factor

divide x^3 + 3x^2 - 13x -15 by x+1 and factor the result to find the two remaining roots