Question

$(8 { - }^{2} + 9 { - }^{2} + 6 { - }^{2} )$
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Answer 1

Step-by-step explanation:

8-²+9-²+6-²

=√8+√9+√6

=2√2+3+√6

=5√2+√6

Answer 2

Answer:

$\frac{289}{5184}$

Step-by-step explanation:

$( {8}^{ - 2} + {9}^{ - 2} + {6}^{ - 2} ) \\ \\ = ( \frac{1}{ {8}^{2} } + \frac{1}{ {9}^{2} } + \frac{1}{ {6}^{2} } ) \\ \\ = ( \frac{1}{64} + \frac{1}{81} + \frac{1}{36} ) \\ \\ (lcm \: of \: 64 \: 81 \: and \: 36 \: is \: 5184) \\ \\ = ( \frac{(1 \times 81) + (1 \times 64) + (1 \times 144)}{5184} \\ \\ = ( \frac{81 + 64 + 144}{5184}) \\ \\ = \frac{289}{5184}$

Hence

${9}^{ - 2} + {8}^{ - 2} + {6}^{ - 2} = \frac{289}{5184}$

hope it helps.