Question 625717
Evaluate: 3^-1-6^-1
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= {{{3^-1/1 - 6^-1/1}}}
For 3^-1, multiply NUM & DEN by 3^1

= {{{(3^-1*3^1)/3^1 - 6^-1/1}}}
= {{{(3^0)/3^1 - 6^-1/1}}}
3^0 = 1
= {{{1/3^1 - 6^-1/1}}}
= {{{1/3 - 6^-1/1}}}
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Notice that the sign of the exponent changes, and it moves from NUM to DEN.
The vice versa is also true.
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Doing the same for 6^-1,
= {{{1/3 - 1/6}}}
= 1/6