(у/(у-5) - 2у) : (11-2у)/(у-5) = (у-2у(у-5))/(у-5) : (11-2у)/(у-5) =
= (у-2у²+10у)/(у-5) * (у-5)/(11-2у) = (11у-2у²)/(11-2у) = (у(11-2у))/(11-2у) = у
Loga(ab )=Loga(a)+Loga(b)=1+5=6
Раскроем скобки<span>6х²-4х+9х-6-5х²-20х-5х-20-20х+х²=и просто посчитай)</span>