FACTORING POLYNOMIALS USING SYNTHETIC DIVISION

In this section, we use the synthetic division method that helps to factor a cubic polynomial into linear factors. If we identify one linear factor of cubic polynomial p(x) then using synthetic division we can get the quadratic factor of p(x). Further if possible one can factor the quadratic factor into linear factors.

Factor each of the following polynomials using synthetic division :

Example 1 :

x3 - 3x2 - 10x + 24

Solution :

By Substituting x = 2, we get the remainder 0.

So (x - 2) is a factor.

Then, 

x2 - x - 12 = x2 - 4x + 3x - 12

x2 - x - 12 = x(x - 4) + 3(x - 4)

x2 - x - 12 = (x + 3)(x - 4)

Therefore, the factors are (x - 2)(x + 3)(x- 4).

Example 2 :

2x3 - 3x2 - 3x + 2

Solution :

By substituting x = -1, we get the remainder 0.

So (x + 1) is a factor.

Then,

2x2 - 5x + 2 = 2x2 - 4x - x + 2

2x2 - 5x + 2 = 2x(x - 2) - 1(x - 2)

2x2 - 5x + 2 = (2x - 1)(x - 2)

Therefore, the factors are (x + 1)(2x - 1)(x - 2).

Example 3 :

-7x + 3 + 4x3

Solution :

-7x + 3 + 4x3  =  4x3 + 0x2 - 7x + 3

By substituting x = 1, we get the remainder 0.

So (x - 1) is a factor.

Then,

4x2 + 4x - 3 = 4x2 + 6x - 2x - 3

4x2 + 4x - 3 = 2x(2x + 3) - 1(2x + 3)

4x2 + 4x - 3 = (2x - 1)(2x + 3)

Therefore, the factors are (x - 1)(2x - 1)(2x + 3).

Example 4 :

x3 + x2 - 14x - 24

Solution :

By substituting x = -2, we get the remainder 0.

So (x + 2) is a factor.

Then,

x2 - x - 12 = x2 - 4x  + 3x - 12

x2 - x - 12 = x(x - 4) + 3(x - 4)

x2 - x - 12 = (x + 3)(x - 4)

Therefore, the factors are (x + 2)(x + 3)(x - 4).

Example 5 :

x3  - 7x + 6

Solution :

By substituting x = 1, we get the remainder 0.

So (x - 1) is a factor.

Then,

x2 + x - 6 = x2 + 3x  - 2x - 6

x2 + x - 6 = x(x + 3) - 2(x + 3)

x2 + x - 6 = (x + 3)(x - 2)

Therefore, the factors are (x - 2)(x + 3)(x - 1).

Example 6 :

x3 - 10x2 - x + 10

Solution :

By substituting x = 1, we get the remainder 0.

So (x - 1) is a factor.

Then,

x2 - 9x - 10 = x2 - 10x + 1x - 10

x2 - 9x - 10 = x(x - 10) + 1(x - 10)

x2 - 9x - 10 = (x + 1)(x - 10)

Therefore, the factors are (x + 1)(x - 10)(x - 1).

Kindly mail your feedback to v4formath@gmail.com

We always appreciate your feedback.

©All rights reserved. onlinemath4all.com

Recent Articles

  1. Printable Math Worksheets

    Apr 20, 24 12:02 AM

    Printable Math Worksheets - Worksheets in Pdf formats from grade 1 to 10

    Read More

  2. Printable Math Worksheets for Grade 2

    Apr 19, 24 11:58 PM

    Printable Math Worksheets for Grade 2

    Read More

  3. Sequences and Series

    Apr 19, 24 11:45 PM

    Sequences and Series - Concept - Examples

    Read More