Simplify the Rational Expression $$\frac { 81 - x ^ { 2 } } { x ^ { 2 } - 13 x + 36 }$$

question 86

Multiple Choice

Simplify the rational expression. If the rational expression cannot be simplified, so state.
- $$\frac { 81 - x ^ { 2 } } { x ^ { 2 } - 13 x + 36 }$$

• A) \(- \frac { x + 9 } { x + 4 }\)
• B) \(- \frac { x - 9 } { x - 4 }\)
• C) \(- \frac { x + 9 } { x - 4 }\)
• D) \(\frac { x + 9 } { x - 4 }\)

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Definitions:

Euchromatin

A lightly packed form of chromatin (DNA, RNA, and protein complex) that is enriched in gene concentration and is active in transcription.

Barr Bodies

Inactivated X chromosomes found in the nuclei of cells in female organisms, visible as a dense mass, and a key component in dosage compensation.

Promoters

DNA sequences located near the beginning of a gene that signal RNA polymerase where to start transcription.

Frameshift Mutation

A genetic mutation caused by insertions or deletions of a number of nucleotides in a DNA sequence that is not divisible by three, altering the reading frame.