Question 41945
1. (1/2)-1 = 1/2^-1 = 1/(1/2)^1 = 2
When a a number is raised to a negative exponent, turn it into a positive exponent by taking the inverse of the number.  To get the inverse, just flip the number and place it under or ontop of 1 (depending on the problem).
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Example:  3^(-2) = Flip it = 1/3^2
The inverse of 3 is 1/3.  Be sure to include the positive exponent.

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Example 1/3^-2 = Flip it = 3^2.
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2. 73 with 0 power = 73^0 = 0
Any number raised to zero equals zero.
Example:  3^0 = 0
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3. 13-x= 13^(-x) = Flip it =  1/(13^x)
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4. 4-2= 4^(-2) = Flip it = 1/4^(2) = 1/16