SOLUTION: 1-list the possible rational roots for 5x^8 -x^7 + 6x^6 - 7x + 8, as given by the rational roots theorem 2- if -5 is one root of x^3 + x^2 -15x + 25, what are the others?

Algebra ->  Rational-functions -> SOLUTION: 1-list the possible rational roots for 5x^8 -x^7 + 6x^6 - 7x + 8, as given by the rational roots theorem 2- if -5 is one root of x^3 + x^2 -15x + 25, what are the others?      Log On


   

Question 757631: 1-list the possible rational roots for 5x^8 -x^7 + 6x^6 - 7x + 8, as given by the rational roots theorem
2- if -5 is one root of x^3 + x^2 -15x + 25, what are the others?
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
1-list the possible rational roots for 5x^8 -x^7 + 6x^6 - 7x + 8, as given by the rational roots theorem
2- if -5 is one root of x^3 + x^2 -15x + 25, what are the others?
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1. possible rational roots:
for 5x^8 -x^7 + 6x^6 - 7x + 8
..........|..±1......±2........±4........±8
...±1...|..±1......±2.......±4........±8
...±5...|.±1/5..±2/5....±4/5....±8/5
..
2.Using rational roots theory
f(x)= x^3 + x^2 -15x + 25
....0...|....1......1.....-15......25
..-5...|....1....-4.......5.........0
f(x)=(x+5)(x^2-4x+5)
f(x)=(x+5)(x-5)(x+1)
Other roots are: -1 and 5