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[tex]({25})^ { \frac {-1}{2} } + {2}^{ - 2} \times {( \frac{1}{27})}^{ - 3} \\ = { ({5}^{2} )}^ { \frac{ - 1}{2} } + \frac{1}{ {2}^{2} } \times ({ \frac{1}{ {3}^{3} })}^{ - 3} \\ = {5}^{ - 1} + \frac{1}{4} \times ({ {3}^{ - 3} })^{ - 3} \\ = \frac{1}{5} + \frac{1}{4} \times {3}^{ - 6} \\ = \frac{1}{5} + \frac{1}{4} \times \frac{1}{ {3}^{6}} \\ = \frac{1}{5} + \frac{1}{4} \times \frac{1}{729} \\ \frac{1}{5} + \frac{1}{2916} = \frac{2921}{1450} [/tex]
betul gak?