$5^a=10$  

$a={\log }_{5}10$  

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${\left(\frac{1}{4}\right)}^b=7$  

$b={\log }_{\frac{1}{4}}7$  

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${0,02}^c=\frac{2}{3}$  

$c={\log }_{0,02}\left(\frac{2}{3}\right)$  

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$e^d=0,6$  

$d={\ln }_{e}0,6=\ln 0,6$