



 
Hi Ellen, You didn't give instructions but I assume you are to "simplify" or "write without the negative exponent". You have \[\frac{7}{a b^{4}}.\] First of all focus on the denominator alone to get \[a b^{4} = a \times \frac{1}{b^4} = \frac{a}{b^4}.\] The original expression then can be written as \[\frac{7}{\frac{a}{b^4}} = 7 \times \frac{b^4}{a} = \frac{7 b^4}{a}\] I hope this helps, Penny  


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