Question
Simplify: $(4^{-1}-5^{-1})^{-1}\div3^{-1}$
✓
Answer
$(4^{-1}-5^{-1})^{-1}\div3^{-1}$
$=\Big(\frac{1}{4}-\frac{1}{5}\Big)^{-1}\times\frac{1}{3}$
$=\Big(\frac{5-4}{20}\Big)^{-1}\times\frac{3}{1}=\Big(\frac{1}{20}\Big)^{-1}\times\frac{3}{1}$
$=\frac{20}{1}\times\frac{3}{1}=60$
$=\Big(\frac{1}{4}-\frac{1}{5}\Big)^{-1}\times\frac{1}{3}$
$=\Big(\frac{5-4}{20}\Big)^{-1}\times\frac{3}{1}=\Big(\frac{1}{20}\Big)^{-1}\times\frac{3}{1}$
$=\frac{20}{1}\times\frac{3}{1}=60$
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