SOLUTION: I am having trouble solving this type of problems. x^3+5x^2-6x+10 ___________ __ x+3

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I am having trouble solving this type of problems. x^3+5x^2-6x+10 ___________ __ x+3      Log On


   



Question 140099: I am having trouble solving this type of problems.
x^3+5x^2-6x+10
______________
x+3

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

Let's simplify this expression using synthetic division


Start with the given expression %28x%5E3+%2B+5x%5E2+-+6x+%2B+10%29%2F%28x%2B3%29

First lets find our test zero:

x%2B3=0 Set the denominator x%2B3 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.
-3|15-610
|

Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 1)
-3|15-610
|
1

Multiply -3 by 1 and place the product (which is -3) right underneath the second coefficient (which is 5)
-3|15-610
|-3
1

Add -3 and 5 to get 2. Place the sum right underneath -3.
-3|15-610
|-3
12

Multiply -3 by 2 and place the product (which is -6) right underneath the third coefficient (which is -6)
-3|15-610
|-3-6
12

Add -6 and -6 to get -12. Place the sum right underneath -6.
-3|15-610
|-3-6
12-12

Multiply -3 by -12 and place the product (which is 36) right underneath the fourth coefficient (which is 10)
-3|15-610
|-3-636
12-12

Add 36 and 10 to get 46. Place the sum right underneath 36.
-3|15-610
|-3-636
12-1246

Since the last column adds to 46, we have a remainder of 46. This means x%2B3 is not a factor of x%5E3+%2B+5x%5E2+-+6x+%2B+10
Now lets look at the bottom row of coefficients:

The first 3 coefficients (1,2,-12) form the quotient

x%5E2+%2B+2x+-+12

and the last coefficient 46, is the remainder, which is placed over x%2B3 like this

46%2F%28x%2B3%29



Putting this altogether, we get:

x%5E2+%2B+2x+-+12%2B46%2F%28x%2B3%29

So %28x%5E3+%2B+5x%5E2+-+6x+%2B+10%29%2F%28x%2B3%29=x%5E2+%2B+2x+-+12%2B46%2F%28x%2B3%29

which looks like this in remainder form:
%28x%5E3+%2B+5x%5E2+-+6x+%2B+10%29%2F%28x%2B3%29=x%5E2+%2B+2x+-+12 remainder 46


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