SOLUTION: Good Afternoon, HELP ME PLEASE. Find the quotient using the long Division method. I would love to step by step so I can understand it much better. x^3+8 Divid

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Good Afternoon, HELP ME PLEASE. Find the quotient using the long Division method. I would love to step by step so I can understand it much better. x^3+8 Divid      Log On


   



Question 1012998: Good Afternoon,
HELP ME PLEASE.
Find the quotient using the long Division method. I would love to step by step so I can understand it much better.
x^3+8 Divided by x +2

Evaluate the polynomial for X-3 and x=-3, please show me the steps
-3x^3+8x^2-5x-9
Thanking you in advance Betty

Found 2 solutions by Boreal, MathTherapy:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
====x^2-2x+4
x+2/x^3+0x^2+0x+8
====x^3+2x^2
change sign and add
======-2x^2+8
======-2x^2-4x
change sign and add
=======4x+8
=======4x+8
change sign and add
0
x^2-2x+4 is the quotient
===============================================
x=-3
-3(-27)+8(-3)^2-5(-3)-9
81+72+15-9=159
==================
-3(x-3)^3+8(x-3)^2-5(x-3)-9;(x-3)^3=(x^2-6x+9)(x-3)=x^3-9x^2+27x-27
(x-3)^2=x^2-6x+9
the first has to be multiplied by -3
-3x^3+27x^2-81x+81 add the second multiplied by 8
====8x^2-48x+72 add the third multiplied by -5
====== -5x+15
============-9
-3x^3+35x^2-134x+159.




Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
Good Afternoon,
HELP ME PLEASE.
Find the quotient using the long Division method. I would love to step by step so I can understand it much better.
x^3+8 Divided by x +2

Evaluate the polynomial for X-3 and x=-3, please show me the steps
-3x^3+8x^2-5x-9
Thanking you in advance Betty
             x² - 2x  + 4
x + 2|x³ + 0x² + 0x + 8
x³ + 2x²
- 2x² + 0x
- 2x² - 4x
4x + 8
4x + 8
As seen, the quotient is: highlight_green%28x%5E2+-+2x+%2B+4%29
Assuming that you meant that a factor of the polynomial is x - 3, then: x - 3 = 0, so one of its roots is: x = 3
x = 3
-+3x%5E3+%2B+8x%5E2+-+5x+-+9
-+3%283%29%5E3+%2B+8%283%29%5E2+-+5%283%29+-+9
- 3(27) + 8(9) - 15 - 9
- 81 + 72 - 24 -----> highlight_green%28-+33%29
x = - 3
-+3x%5E3+%2B+8x%5E2+-+5x+-+9
-+3%28-+3%29%5E3+%2B+8%28-+3%29%5E2+-+5%28-+3%29+-+9
- 3(- 27) + 8(9) + 15 - 9
81 + 72 + 6 -----> highlight_green%28159%29