SOLUTION: I need help with problems like -6z^-4 (negative 6z to the power of negative 4)

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Question 202699: I need help with problems like -6z^-4 (negative 6z to the power of negative 4)
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
If the problem is -6z%5E%28-4%29, then the correct way to read this is: "negative six times z to the negative fourth power" or "negative six times z to the power of negative four". And the only way to simplify this is to write it with a positive exponent. Using the fact that a%5E%28-n%29+=+1%2F%28a%5En%29, we get %28-6%29%2F%28z%5E4%29.

If the problem is "negative 6z to the power of negative 4", then the correct way to write this is %28-6z%29%5E%28-4%29. Note the parentheses! They are critical. Exponent only apply to whatever is immediately in front of them! With the right parenthesis in front of the exponent, the exponent applies to the entire expression in the parentheses. Without the parentheses the exponent only applies to the z.

To simplify %28-6z%29%5E%28-4%29 we can start by using the a%5E%28-n%29+=+1%2F%28a%5En%29 property to give: 1%2F%28%28-6z%29%5E4%29. Then we can use the property %28a%2Ab%29%5En+=+a%5En+%2A+b%5En to give: 1%2F%28%28-6%29%5E4+%2A+z%5E4%29. Since %28-6%29%5E4+=+1296 we get 1%2F%281296z%5E4%29. (If negative exponents are allowed, then this could alos be written as z%5E%28-4%29%2F1296 or %281%2F1296%29z%5E%28-4%29).