Can you show the steps? thanks a lot
Alix Witvoet
2007-08-28 06:10:58 · 3 answers · asked by Fake Account 1 in Science & Mathematics ➔ Mathematics
Factor (b + 5) out:
b^3 + 5b^2 - b - 5
= b^2(b + 5) - (b + 5)
= (b + 5)(b^2 - 1)
= (b + 5)(b + 1)(b - 1)
The roots are:
-5, -1, and 1
2007-08-28 06:20:04 · answer #1 · answered by Anonymous · 0⤊ 0⤋
No I can't show you the steps, that would take me 1/2 hour to type..............and it's probably YOUR homework.
Here's a clue though, B + 1 is a factor, so just divide that into the expression you gave, that will give you a quadratic and you can solve that with the conventional formula.
2007-08-28 13:23:43 · answer #2 · answered by andyg77 7 · 0⤊ 0⤋
b³ + 5b² - b - 5 = 0
1² + 5 (1²) - (1) - 5 = 0 so b - 1 is a factor
To find other factors , use synthetic division:-
"""""""|1"""" 5""""" -1"""""" -5
"""""1|"""""" 1"""""" 6""""""" 5
"""""""|1"""" 6"""""" 5""""""" 0
(b - 1)(b² + 6b + 5) = 0
(b - 1)(b + 5)(b + 1) = 0
b = 1 , b = - 5 , b = - 1
2007-09-02 07:16:34 · answer #3 · answered by Como 7 · 0⤊ 0⤋