Given that P(x) = x^4 + ax^3 - x^2 + bx - 12 has factors x - 2 and and x + 1, how do you solve the equation P(x) = 0?

1 Answer
Sep 26, 2015

This equation has 4 solutions: x1=3, x2=2, x3=1 and x4=2

Explanation:

According to Viete's Theorem if P(x) has a factor of (xa) then a is a root of this polynomial, so in this case this polynomial has 2 roots: x3=1 and x4=2.

To find the other roots you have to divide P(x) by (x2)(x+1). The result will be: x2+5x+6.

Then you can calculate the remaining roots.