Question

решите log1/9(9-x)=-2

Answer 1

$log_{ frac{1}{9}}(9-x)=-2\\OD3:9-x textgreater 0\x textless 9\\ log_{ frac{1}{9}}(9-x)=log_{ frac{1}{9}}( frac{1}{9}^{-2} )\\log_{ frac{1}{9}}(9-x)=log_{ frac{1}{9}}81\\9-x=81\\x=9-81\\x=-72 ( textless 9)$

Ответ: -72