6^lgx=72-x^lg6 ;
6^lgx +x^lg6=72 ; * * * x^lg6 = 6^lgx _правила перекладина * * *
2*(6^lgx) =72 ;
(6^lgx) =6² ;
lgx =2⇒ x=100.
ответ : 100 .
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(Log_b c) *(Log_b a) =(Log_b a)*(Log_b c )⇔
Log_b (a ^ Log_b c) = Log_b (c^ Log_b a) ⇒a ^ Log_b c = c^ Log_b a.