Negative Integer Exponents
Here is a summary of our work with negative exponents:
| Definition |
Example 1 |
Example 2 |
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Here, the variables represent nonzero real numbers and n is a nonnegative
integer.
Example 1
Find:
| Solution |
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Use the definition of a negative exponent,
 |
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| Evaluate the exponential expressions. |
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| In the denominator of the expression, write each
fraction using the LCD, 18. |
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| In the denominator of the expression, subtract
the fractions.
|
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| Rewrite the division using ÷.
|
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To divide 5 by a fraction, multiply
 by the
reciprocal of the fraction.
|
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| Multiply the numerators and multiply the denominators.
|
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Thus,
Example 2
Rewrite using only positive exponents:
Solution
| Since -7 is the exponent of y, not 5y, 5y -7 =
5 · y -7 |
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Use the definition
 |
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Thus,
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