Polynomial Long Division: (4x^4 + 18x^3 + 20x^2 + 10x + 8) ÷ (x + 2)
This article will guide you through the process of dividing the polynomial 4x^4 + 18x^3 + 20x^2 + 10x + 8 by the binomial x + 2 using long division.
Steps for Polynomial Long Division
-
Set up the division. Write the dividend (4x^4 + 18x^3 + 20x^2 + 10x + 8) inside the division symbol and the divisor (x + 2) outside.
___________________ x + 2 | 4x^4 + 18x^3 + 20x^2 + 10x + 8
-
Divide the leading terms. Divide the leading term of the dividend (4x^4) by the leading term of the divisor (x). The result is 4x^3. Write this above the division symbol.
4x^3 ___________________ x + 2 | 4x^4 + 18x^3 + 20x^2 + 10x + 8
-
Multiply the divisor by the quotient term. Multiply (x + 2) by 4x^3, which gives 4x^4 + 8x^3. Write this result below the dividend.
4x^3 ___________________ x + 2 | 4x^4 + 18x^3 + 20x^2 + 10x + 8 4x^4 + 8x^3
-
Subtract. Subtract the result from the dividend.
4x^3 ___________________ x + 2 | 4x^4 + 18x^3 + 20x^2 + 10x + 8 4x^4 + 8x^3 ----------- 10x^3
-
Bring down the next term. Bring down the next term of the dividend (20x^2).
4x^3 ___________________ x + 2 | 4x^4 + 18x^3 + 20x^2 + 10x + 8 4x^4 + 8x^3 ----------- 10x^3 + 20x^2
-
Repeat steps 2-5. Divide the new leading term (10x^3) by the leading term of the divisor (x) to get 10x^2. Write this above the division symbol.
4x^3 + 10x^2 ___________________ x + 2 | 4x^4 + 18x^3 + 20x^2 + 10x + 8 4x^4 + 8x^3 ----------- 10x^3 + 20x^2
Multiply (x + 2) by 10x^2 and subtract the result.
4x^3 + 10x^2 ___________________ x + 2 | 4x^4 + 18x^3 + 20x^2 + 10x + 8 4x^4 + 8x^3 ----------- 10x^3 + 20x^2 10x^3 + 20x^2 ----------- 0
-
Bring down the next term. Bring down the next term of the dividend (10x).
4x^3 + 10x^2 ___________________ x + 2 | 4x^4 + 18x^3 + 20x^2 + 10x + 8 4x^4 + 8x^3 ----------- 10x^3 + 20x^2 10x^3 + 20x^2 ----------- 0 + 10x
-
Repeat steps 2-5. Divide (10x) by (x) to get 10.
4x^3 + 10x^2 + 10 ___________________ x + 2 | 4x^4 + 18x^3 + 20x^2 + 10x + 8 4x^4 + 8x^3 ----------- 10x^3 + 20x^2 10x^3 + 20x^2 ----------- 0 + 10x
Multiply (x + 2) by 10 and subtract.
4x^3 + 10x^2 + 10 ___________________ x + 2 | 4x^4 + 18x^3 + 20x^2 + 10x + 8 4x^4 + 8x^3 ----------- 10x^3 + 20x^2 10x^3 + 20x^2 ----------- 0 + 10x + 8 10x + 20 ----- -12
-
The remainder is -12. Since the degree of the remainder (-12) is less than the degree of the divisor (x+2), we stop here.
Solution:
The result of dividing (4x^4 + 18x^3 + 20x^2 + 10x + 8) by (x + 2) is:
4x^3 + 10x^2 + 10 - (12/(x + 2))
This can also be written as:
4x^3 + 10x^2 + 10 + (-12)/(x + 2)