Answer:
A/(x+7) +B/(x+4)
Step-by-step explanation:
The denominators of the partial fraction expansion are the factors of the denominator of the rational function.
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Here, the rational function's denominator can be factored as ...
x² +11x +28 = (x +7)(x +4)
Then the form of the decomposition is ...
[tex]\dfrac{x-2}{x^2+11x+28}=\boxed{\dfrac{A}{x+7}+\dfrac{B}{x+4}}[/tex]
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Additional comment
Here, A=3. B=-2.
If the factors of the denominator have multiplicity greater than 1, then there is a fraction with each power of that factor up to the multiplicity. For example, if there is a factor (x+4)³, then the decomposition would include fractions A/(x+4) +B/(x+4)² +C/(x+4)³.
