SOLUTION: Divide (2x^3-8x^2-4x-6)/(x-3) using synthetic division

Algebra ->  Equations -> SOLUTION: Divide (2x^3-8x^2-4x-6)/(x-3) using synthetic division      Log On


   



Question 205263: Divide (2x^3-8x^2-4x-6)/(x-3) using synthetic division
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
Divide %282x%5E3-8x%5E2-4x-6%29%2F%28x-3%29 using synthetic division

Change the sign of the -3 in x-3 to %22%22%2B3

Start with this

3 | 2 -8  -4  -6
  |   
   -------------

Bring down the 2    

3 | 2 -8  -4  -6
  |    
   -------------
    2 

Multiply the 2 by the 3, getting 6.
Then write it above and to the right
of the 2:


3 | 2 -8  -4  -6
  |    6  
   -------------
    2 

Combine the -8 and the 6, getting -2 and
write it at the bottom:

3 | 2 -8  -4  -6
  |    6  
   -------------
    2 -2 

Multiply the -2 by the 3, getting -6.
Then write it above and to the right
of the -2:


3 | 2 -8  -4  -6
  |    6  -6 
   -------------
    2 -2 

Combine the -4 and the -6, getting -10 and
write it at the bottom:

3 | 2 -8  -4  -6
  |    6  -6 
   -------------
    2 -2 -10 

Multiply the -10 by the 3, getting -30.
Then write it above and to the right
of the -10:


3 | 2 -8  -4  -6
  |    6  -6 -30
   -------------
    2 -2 -10 

Combine the -6 and the -30, getting -36 and
write it at the bottom:

3 | 2 -8  -4  -6
  |    6  -6 -30
   -------------
    2 -2 -10 -36

Now we interpret that bottom line of numbers:
The largest power of x in the original numerator
2x%5E3-8x%5E2-4x-6 is 3.  So subtract one from
3 and get 2 for the exponent of x.  So the first
three numbers on the bottom is to be interpreted 
as

  2x%5E2-2x-10

Then the last number, -36, is the remainder and
we put that over the original divisor x-3
and this fraction is added to the quotient:

  2x%5E2-2x-10%2B%28-36%29%2F%28x-3%29

Now we can just write that as MINUS that fraction:

  2x%5E2-2x-10-36%2F%28x-3%29 

Edwin