Question

(5raise-1-7raise-1)raise-1​

Answer 1

$\red{ Value \: of \: ( 5^{-1} - 7^{-1})^{-1} }$

$= \Big( \frac{1}{5} - \frac{1}{7}\Big)^{-1}$

$= \Big( \frac{7-5}{35} \Big)^{-1}$

$= \Big( \frac{2}{35} \Big)^{-1}$

$= \Big( \frac{35}{2} \Big)^{1}$

Therefore.,

$\red{ Value \: of \: ( 5^{-1} - 7^{-1})^{-1} }$

$\green {= \frac{35}{2}}$

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Answer 2

$\star\:\:\:\bf\large\underline\blue{Question:-}$

• Evaluate.

$\star\:\:\:\bf\large\underline\blue{Solution:-}$

${( {5}^{ - 1} - {7}^{ - 1} )}^{ - 1 }$

$= {( \frac{1}{5} - \frac{1}{7}) }^{ - 1}$

$= {( \frac{7 - 5}{35} ) }^{ - 1}$

$= {( \frac{2}{35} ) }^{ - 1}$

$= \frac{35}{2}$

$= 17.5$

$\star\:\:\:\bf\large\underline\blue{Answer:-}$

• $17.5$