Question

use the rational root theorem and the factor theorem to help solve the following equation

X^4-4x^3+14x^2-19x+28=0

A) (-10, -1, 0, 1/4)
B) (-10, -1, 0, 4)
C) (+-10, -1, 4)
D) no rational solution

Answer 1

no rational solution

Answer 2

Try 0 (because it is in choice A and B, and it's easy to evaluate)
28≠0 so A and B are out.

Answer 3

C has a -1. That isn't too hard
1+4+14+19+28 that isn't 0
so we are left with D