Question 878113
{{{(-7)^-4}}}
= {{{(-7)^-4/1}}}
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Multiply NUM and DEN by (-7)^4
= {{{(-7)^-4*(-7)^4/(1*7^(4))}}}
= {{{(-7)^0/7^4}}}
= {{{1/7^4}}}
= 1/2401
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I lost a minus sign along the way, but since it's an even power, it has no effect.