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. Problems on Numbers with Solutions

    Oct 23, 24 05:36 AM

    Problems on Numbers with Solutions

    Read More

  2. Digital SAT Math Problems and Solutions (Part - 57)

    Oct 22, 24 06:52 AM

    Digital SAT Math Problems and Solutions (Part - 57)

    Read More

  3. Solving Exponential Equations Problems and Solutions (Part - 6)

    Oct 21, 24 03:23 AM

    Solving Exponential Equations Problems and Solutions (Part - 6)

    Read More