Find the [tex]$HCF$[/tex] of the following pairs of polynomials:

1. [tex]12\left(x^3+x^2+x+1\right)[/tex] and [tex]18\left(x^4-1\right)[/tex]
2. [tex]4\left(x^4-1\right)[/tex] and [tex]6\left(x^3-x^2-x+1\right)[/tex]
3. [tex]18\left(6 x^4+x^3-x^2\right)[/tex] and [tex]45\left(2 x^6+3 x^5+x^4\right)[/tex]
4. [tex]2 x^2-x-1[/tex] and [tex]4 x^2+8 x+3[/tex]
5. [tex]2 x^2-18[/tex] and [tex]x^2-2 x-3[/tex]



Answer :

To find the Highest Common Factor (HCF) of the given pairs of polynomials, we need to determine the greatest common divisor of each pair. Below is a step-by-step explanation for each pair of polynomials:

1. For the pair: \(12(x^3 + x^2 + x + 1)\) and \(18(x^4 - 1)\)

Let's start with the polynomials:
[tex]\[ 12(x^3 + x^2 + x + 1) \quad \text{and} \quad 18(x^4 - 1) \][/tex]

The HCF of these polynomials is:
[tex]\[ 6(x^3 + x^2 + x + 1) \][/tex]

2. For the pair: \(4(x^4 - 1)\) and \(6(x^3 - x^2 - x + 1)\)

Let's start with the polynomials:
[tex]\[ 4(x^4 - 1) \quad \text{and} \quad 6(x^3 - x^2 - x + 1) \][/tex]

The HCF of these polynomials is:
[tex]\[ 2(x^2 - 1) \][/tex]

3. For the pair: \(18(6x^4 + x^3 - x^2)\) and \(45(2x^6 + 3x^5 + x^4)\)

Let's start with the polynomials:
[tex]\[ 18(6x^4 + x^3 - x^2) \quad \text{and} \quad 45(2x^6 + 3x^5 + x^4) \][/tex]

The HCF of these polynomials is:
[tex]\[ 18(x^3 + \frac{1}{2}x^2) = 18x^3 + 9x^2 \][/tex]

4. For the pair: \(2x^2 - x - 1\) and \(4x^2 + 8x + 3\)

Let's start with the polynomials directly:
[tex]\[ 2x^2 - x - 1 \quad \text{and} \quad 4x^2 + 8x + 3 \][/tex]

The HCF of these polynomials is:
[tex]\[ 2x + 1 \][/tex]

5. For the pair: \(2x^2 - 18\) and \(x^2 - 2x - 3\)

Let's start with the polynomials directly:
[tex]\[ 2x^2 - 18 \quad \text{and} \quad x^2 - 2x - 3 \][/tex]

The HCF of these polynomials is:
[tex]\[ x - 3 \][/tex]

Therefore, the HCFs for the given pairs of polynomials are as follows:
1. \(6x^3 + 6x^2 + 6x + 6\)
2. \(2x^2 - 2\)
3. \(18x^3 + 9x^2\)
4. \(2x + 1\)
5. [tex]\(x - 3\)[/tex]