Precalculus Examples

Split Using Partial Fraction Decomposition (80x^3+24x^2-2x+11)/(40x^2+12x-16)
Step 1
Divide using long polynomial division.
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Step 1.1
Set up the polynomials to be divided. If there is not a term for every exponent, insert one with a value of .
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Step 1.2
Divide the highest order term in the dividend by the highest order term in divisor .
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Step 1.3
Multiply the new quotient term by the divisor.
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++-
Step 1.4
The expression needs to be subtracted from the dividend, so change all the signs in
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Step 1.5
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
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--+
+
Step 1.6
Pull the next term from the original dividend down into the current dividend.
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++
Step 1.7
The final answer is the quotient plus the remainder over the divisor.
Step 2
Decompose the fraction and multiply through by the common denominator.
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Step 2.1
Factor the fraction.
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Step 2.1.1
Factor out of .
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Step 2.1.1.1
Factor out of .
Step 2.1.1.2
Factor out of .
Step 2.1.1.3
Factor out of .
Step 2.1.1.4
Factor out of .
Step 2.1.1.5
Factor out of .
Step 2.1.2
Factor.
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Step 2.1.2.1
Factor by grouping.
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Step 2.1.2.1.1
For a polynomial of the form , rewrite the middle term as a sum of two terms whose product is and whose sum is .
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Step 2.1.2.1.1.1
Factor out of .
Step 2.1.2.1.1.2
Rewrite as plus
Step 2.1.2.1.1.3
Apply the distributive property.
Step 2.1.2.1.2
Factor out the greatest common factor from each group.
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Step 2.1.2.1.2.1
Group the first two terms and the last two terms.
Step 2.1.2.1.2.2
Factor out the greatest common factor (GCF) from each group.
Step 2.1.2.1.3
Factor the polynomial by factoring out the greatest common factor, .
Step 2.1.2.2
Remove unnecessary parentheses.
Step 2.2
For each factor in the denominator, create a new fraction using the factor as the denominator, and an unknown value as the numerator. Since the factor in the denominator is linear, put a single variable in its place .
Step 2.3
For each factor in the denominator, create a new fraction using the factor as the denominator, and an unknown value as the numerator. Since the factor in the denominator is linear, put a single variable in its place .
Step 2.4
Multiply each fraction in the equation by the denominator of the original expression. In this case, the denominator is .
Step 2.5
Cancel the common factor of .
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Step 2.5.1
Cancel the common factor.
Step 2.5.2
Rewrite the expression.
Step 2.6
Cancel the common factor of .
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Step 2.6.1
Cancel the common factor.
Step 2.6.2
Rewrite the expression.
Step 2.7
Cancel the common factor of .
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Step 2.7.1
Cancel the common factor.
Step 2.7.2
Divide by .
Step 2.8
Simplify each term.
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Step 2.8.1
Cancel the common factor of .
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Step 2.8.1.1
Cancel the common factor.
Step 2.8.1.2
Divide by .
Step 2.8.2
Rewrite using the commutative property of multiplication.
Step 2.8.3
Apply the distributive property.
Step 2.8.4
Rewrite using the commutative property of multiplication.
Step 2.8.5
Multiply by .
Step 2.8.6
Multiply by .
Step 2.8.7
Cancel the common factor of .
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Step 2.8.7.1
Cancel the common factor.
Step 2.8.7.2
Divide by .
Step 2.8.8
Rewrite using the commutative property of multiplication.
Step 2.8.9
Apply the distributive property.
Step 2.8.10
Rewrite using the commutative property of multiplication.
Step 2.8.11
Multiply by .
Step 2.8.12
Multiply by .
Step 2.9
Reorder.
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Step 2.9.1
Move .
Step 2.9.2
Move .
Step 2.9.3
Move .
Step 3
Create equations for the partial fraction variables and use them to set up a system of equations.
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Step 3.1
Create an equation for the partial fraction variables by equating the coefficients of from each side of the equation. For the equation to be equal, the equivalent coefficients on each side of the equation must be equal.
Step 3.2
Create an equation for the partial fraction variables by equating the coefficients of the terms not containing . For the equation to be equal, the equivalent coefficients on each side of the equation must be equal.
Step 3.3
Set up the system of equations to find the coefficients of the partial fractions.
Step 4
Solve the system of equations.
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Step 4.1
Solve for in .
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Step 4.1.1
Rewrite the equation as .
Step 4.1.2
Subtract from both sides of the equation.
Step 4.1.3
Divide each term in by and simplify.
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Step 4.1.3.1
Divide each term in by .
Step 4.1.3.2
Simplify the left side.
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Step 4.1.3.2.1
Cancel the common factor of .
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Step 4.1.3.2.1.1
Cancel the common factor.
Step 4.1.3.2.1.2
Divide by .
Step 4.1.3.3
Simplify the right side.
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Step 4.1.3.3.1
Simplify each term.
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Step 4.1.3.3.1.1
Cancel the common factor of and .
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Step 4.1.3.3.1.1.1
Factor out of .
Step 4.1.3.3.1.1.2
Cancel the common factors.
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Step 4.1.3.3.1.1.2.1
Factor out of .
Step 4.1.3.3.1.1.2.2
Cancel the common factor.
Step 4.1.3.3.1.1.2.3
Rewrite the expression.
Step 4.1.3.3.1.2
Cancel the common factor of and .
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Step 4.1.3.3.1.2.1
Factor out of .
Step 4.1.3.3.1.2.2
Cancel the common factors.
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Step 4.1.3.3.1.2.2.1
Factor out of .
Step 4.1.3.3.1.2.2.2
Cancel the common factor.
Step 4.1.3.3.1.2.2.3
Rewrite the expression.
Step 4.1.3.3.1.3
Move the negative in front of the fraction.
Step 4.2
Replace all occurrences of with in each equation.
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Step 4.2.1
Replace all occurrences of in with .
Step 4.2.2
Simplify the right side.
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Step 4.2.2.1
Simplify .
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Step 4.2.2.1.1
Simplify each term.
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Step 4.2.2.1.1.1
Apply the distributive property.
Step 4.2.2.1.1.2
Cancel the common factor of .
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Step 4.2.2.1.1.2.1
Factor out of .
Step 4.2.2.1.1.2.2
Cancel the common factor.
Step 4.2.2.1.1.2.3
Rewrite the expression.
Step 4.2.2.1.1.3
Multiply by .
Step 4.2.2.1.1.4
Multiply .
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Step 4.2.2.1.1.4.1
Multiply by .
Step 4.2.2.1.1.4.2
Combine and .
Step 4.2.2.1.1.4.3
Multiply by .
Step 4.2.2.1.1.5
Move the negative in front of the fraction.
Step 4.2.2.1.2
To write as a fraction with a common denominator, multiply by .
Step 4.2.2.1.3
Simplify terms.
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Step 4.2.2.1.3.1
Combine and .
Step 4.2.2.1.3.2
Combine the numerators over the common denominator.
Step 4.2.2.1.4
Simplify each term.
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Step 4.2.2.1.4.1
Simplify the numerator.
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Step 4.2.2.1.4.1.1
Factor out of .
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Step 4.2.2.1.4.1.1.1
Factor out of .
Step 4.2.2.1.4.1.1.2
Factor out of .
Step 4.2.2.1.4.1.1.3
Factor out of .
Step 4.2.2.1.4.1.2
Multiply by .
Step 4.2.2.1.4.1.3
Subtract from .
Step 4.2.2.1.4.1.4
Multiply by .
Step 4.2.2.1.4.2
Move the negative in front of the fraction.
Step 4.3
Solve for in .
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Step 4.3.1
Rewrite the equation as .
Step 4.3.2
Move all terms not containing to the right side of the equation.
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Step 4.3.2.1
Subtract from both sides of the equation.
Step 4.3.2.2
Subtract from .
Step 4.3.3
Multiply both sides of the equation by .
Step 4.3.4
Simplify both sides of the equation.
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Step 4.3.4.1
Simplify the left side.
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Step 4.3.4.1.1
Simplify .
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Step 4.3.4.1.1.1
Cancel the common factor of .
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Step 4.3.4.1.1.1.1
Move the leading negative in into the numerator.
Step 4.3.4.1.1.1.2
Move the leading negative in into the numerator.
Step 4.3.4.1.1.1.3
Factor out of .
Step 4.3.4.1.1.1.4
Cancel the common factor.
Step 4.3.4.1.1.1.5
Rewrite the expression.
Step 4.3.4.1.1.2
Cancel the common factor of .
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Step 4.3.4.1.1.2.1
Factor out of .
Step 4.3.4.1.1.2.2
Cancel the common factor.
Step 4.3.4.1.1.2.3
Rewrite the expression.
Step 4.3.4.1.1.3
Multiply.
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Step 4.3.4.1.1.3.1
Multiply by .
Step 4.3.4.1.1.3.2
Multiply by .
Step 4.3.4.2
Simplify the right side.
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Step 4.3.4.2.1
Simplify .
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Step 4.3.4.2.1.1
Cancel the common factor of .
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Step 4.3.4.2.1.1.1
Move the leading negative in into the numerator.
Step 4.3.4.2.1.1.2
Factor out of .
Step 4.3.4.2.1.1.3
Factor out of .
Step 4.3.4.2.1.1.4
Cancel the common factor.
Step 4.3.4.2.1.1.5
Rewrite the expression.
Step 4.3.4.2.1.2
Combine and .
Step 4.3.4.2.1.3
Multiply by .
Step 4.4
Replace all occurrences of with in each equation.
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Step 4.4.1
Replace all occurrences of in with .
Step 4.4.2
Simplify the right side.
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Step 4.4.2.1
Simplify .
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Step 4.4.2.1.1
Simplify each term.
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Step 4.4.2.1.1.1
Combine and .
Step 4.4.2.1.1.2
Multiply by .
Step 4.4.2.1.1.3
Cancel the common factor of and .
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Step 4.4.2.1.1.3.1
Factor out of .
Step 4.4.2.1.1.3.2
Cancel the common factors.
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Step 4.4.2.1.1.3.2.1
Factor out of .
Step 4.4.2.1.1.3.2.2
Cancel the common factor.
Step 4.4.2.1.1.3.2.3
Rewrite the expression.
Step 4.4.2.1.1.4
Multiply the numerator by the reciprocal of the denominator.
Step 4.4.2.1.1.5
Cancel the common factor of .
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Step 4.4.2.1.1.5.1
Cancel the common factor.
Step 4.4.2.1.1.5.2
Rewrite the expression.
Step 4.4.2.1.2
Combine fractions.
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Step 4.4.2.1.2.1
Combine the numerators over the common denominator.
Step 4.4.2.1.2.2
Simplify the expression.
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Step 4.4.2.1.2.2.1
Subtract from .
Step 4.4.2.1.2.2.2
Divide by .
Step 4.5
List all of the solutions.
Step 5
Replace each of the partial fraction coefficients in with the values found for and .