(2x4+5x3+8x+24)÷(x+2)

5 min read Jun 16, 2024
(2x4+5x3+8x+24)÷(x+2)

Factoring and Dividing Polynomials: (2x⁴ + 5x³ + 8x + 24) ÷ (x + 2)

This article explores the process of dividing the polynomial (2x⁴ + 5x³ + 8x + 24) by the binomial (x + 2). We'll use polynomial long division to achieve this.

Understanding Polynomial Long Division

Polynomial long division is analogous to long division with numbers. It involves a systematic process of dividing a polynomial (the dividend) by another polynomial (the divisor) to obtain a quotient and a remainder.

Steps for Polynomial Long Division

  1. Set up the division:

         _________
    x + 2 | 2x⁴ + 5x³ + 0x² + 8x + 24
    
  2. Divide the leading terms: Divide the leading term of the dividend (2x⁴) by the leading term of the divisor (x), which gives 2x³. Write this quotient above the dividend.

         2x³ ______
    x + 2 | 2x⁴ + 5x³ + 0x² + 8x + 24
    
  3. Multiply the quotient by the divisor: Multiply the quotient (2x³) by the divisor (x + 2), which gives 2x⁴ + 4x³. Write this result below the dividend.

         2x³ ______
    x + 2 | 2x⁴ + 5x³ + 0x² + 8x + 24
            2x⁴ + 4x³
    
  4. Subtract: Subtract the result from the dividend.

         2x³ ______
    x + 2 | 2x⁴ + 5x³ + 0x² + 8x + 24
            2x⁴ + 4x³
            -------
                   x³ + 0x² 
    
  5. Bring down the next term: Bring down the next term from the dividend (0x²).

         2x³ ______
    x + 2 | 2x⁴ + 5x³ + 0x² + 8x + 24
            2x⁴ + 4x³
            -------
                   x³ + 0x² + 8x 
    
  6. Repeat steps 2-5: Repeat the process from step 2 using the new polynomial (x³ + 0x² + 8x).

    • Divide the leading term (x³) by the leading term of the divisor (x), which gives x². Write this above the dividend.
    • Multiply the quotient (x²) by the divisor (x + 2) which gives x³ + 2x².
    • Subtract the result.
    • Bring down the next term (24).
         2x³ + x² _____
    x + 2 | 2x⁴ + 5x³ + 0x² + 8x + 24
            2x⁴ + 4x³
            -------
                   x³ + 0x² + 8x
                   x³ + 2x²
                   -------
                        -2x² + 8x + 24
    
  7. Continue the process: Continue repeating steps 2-5 until the degree of the remainder is less than the degree of the divisor.

    • Divide the leading term (-2x²) by the leading term of the divisor (x), which gives -2x. Write this above the dividend.
    • Multiply the quotient (-2x) by the divisor (x + 2) which gives -2x² - 4x.
    • Subtract the result.
    • Bring down the next term (24).
         2x³ + x² - 2x ____
    x + 2 | 2x⁴ + 5x³ + 0x² + 8x + 24
            2x⁴ + 4x³
            -------
                   x³ + 0x² + 8x
                   x³ + 2x²
                   -------
                        -2x² + 8x + 24
                        -2x² - 4x
                        -------
                               12x + 24
    
  8. Final step:

    • Divide the leading term (12x) by the leading term of the divisor (x), which gives 12. Write this above the dividend.
    • Multiply the quotient (12) by the divisor (x + 2) which gives 12x + 24.
    • Subtract the result.
         2x³ + x² - 2x + 12
    x + 2 | 2x⁴ + 5x³ + 0x² + 8x + 24
            2x⁴ + 4x³
            -------
                   x³ + 0x² + 8x
                   x³ + 2x²
                   -------
                        -2x² + 8x + 24
                        -2x² - 4x
                        -------
                               12x + 24
                               12x + 24
                               -------
                                      0
    

Result

Therefore, (2x⁴ + 5x³ + 8x + 24) ÷ (x + 2) = 2x³ + x² - 2x + 12 with a remainder of 0.

Conclusion

Polynomial long division is a powerful tool for dividing polynomials. It helps us understand the relationships between polynomials and factor them. The steps outlined above provide a systematic method for accurately dividing any polynomial by another.

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