Cрочно!! log7(x-1) log7 x=log7 x
ОДЗ {x>0 {x-1>0⇒x>1 x∈(1;∞) log(7)(x-1*log(7)x-log(70x=0 log(7)x*(log(7)(x-1)-1)=0 log(7)x=0⇒x=1 ∉ОДЗ log(7)(x-1)=1 x-1=7 x=8