Question

evalute the following​

Answer 1

$( ({ \frac{1}{3})}^{ - 2} - { (\frac{1}{9} )}^{ - 2}) \div {3}^{ - 2}$

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Things to remember while doing this are as follows :-

(i) Negative Exponent means reciprocal.

${a}^{ - m} = \frac{1}{ {a}^{m} }$

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(ii) BODMAS rule.

We will be solving bracket first and then division will take place.

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(iii)Division sign can be changed to multiplication sign by reciprocalling any one of the operant

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We will first convert negative exponents to positive by reciprocalling it.

$(({ \frac{1}{3})}^{ - 2} - { (\frac{1}{9} )}^{ - 2}) \div{3}^{ - 2} \\ \\ \\ = ( {3}^{2} - {9}^{2}) \div \frac{1}{ {3}^{2} } \\ \\ \\ = (3 - 9)(3 + 9) \times {3}^{2} \\ \\ \\ \\ = 12 \times ( - 6) \times 9 \\ \\ \\ = 9 \times ( - 72) \\ \\ \\ = ( - 648)$

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Hence,

The value of given expression is equivalent to (-648)

Answer 2

Answer...

( 31 ) −2 −( 91 )

−2 )÷3 −2=(3 2 −9 2)÷ 3 21

=(3−9)(3+9)×3 2

=12×(−6)×9

=9×(−72)

=(−648)

hope it helps!!!