SOLUTION: please me find the answer by useing the Factor Theorem to determine whether (x- 3) is a factor of f(x) = x^4 + 12x^3 + 6x + 27

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Question 92192This question is from textbook Algebra and Trigonometry
: please me find the answer by useing the Factor Theorem to determine whether
(x- 3) is a factor of f(x) = x^4 + 12x^3 + 6x + 27
This question is from textbook Algebra and Trigonometry

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Start with the given polynomial %28x%5E4+%2B+12x%5E3+%2B+6x+%2B+27%29%2F%28x-3%29

First lets find our test zero:

x-3=0 Set the denominator x-3 equal to zero

x=3 Solve for x.

so our test zero is 3


Now set up the synthetic division table by placing the test zero in the upper left corner and placing the coefficients of the numerator to the right of the test zero.(note: remember if a polynomial goes from 12x%5E3 to 6x%5E1 there is a zero coefficient for x%5E2. This is simply because x%5E4+%2B+12x%5E3+%2B+6x+%2B+27 really looks like 1x%5E4%2B12x%5E3%2B0x%5E2%2B6x%5E1%2B27x%5E0
3|1120627
|

Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 1)
3|1120627
|
1

Multiply 3 by 1 and place the product (which is 3) right underneath the second coefficient (which is 12)
3|1120627
|3
1

Add 3 and 12 to get 15. Place the sum right underneath 3.
3|1120627
|3
115

Multiply 3 by 15 and place the product (which is 45) right underneath the third coefficient (which is 0)
3|1120627
|345
115

Add 45 and 0 to get 45. Place the sum right underneath 45.
3|1120627
|345
11545

Multiply 3 by 45 and place the product (which is 135) right underneath the fourth coefficient (which is 6)
3|1120627
|345135
11545

Add 135 and 6 to get 141. Place the sum right underneath 135.
3|1120627
|345135
11545141

Multiply 3 by 141 and place the product (which is 423) right underneath the fifth coefficient (which is 27)
3|1120627
|345135423
11545141

Add 423 and 27 to get 450. Place the sum right underneath 423.
3|1120627
|345135423
11545141450

Since the last column adds to 450, we have a remainder of 450. This means x-3 is not a factor of x%5E4+%2B+12x%5E3+%2B+6x+%2B+27
Now lets look at the bottom row of coefficients:

The first 4 coefficients (1,15,45,141) form the quotient

x%5E3+%2B+15x%5E2+%2B+45x+%2B+141

and the last coefficient 450, is the remainder, which is placed over x-3 like this

450%2F%28x-3%29



Putting this altogether, we get:

x%5E3+%2B+15x%5E2+%2B+45x+%2B+141%2B450%2F%28x-3%29

So

which looks like this in remainder form:
%28x%5E4+%2B+12x%5E3+%2B+6x+%2B+27%29%2F%28x-3%29=x%5E3+%2B+15x%5E2+%2B+45x+%2B+141 remainder 450


You can use this online polynomial division calculator to check your work