log2(3)=a log4(9)=log2^2(3^2)=1/2log2(3^2)=1/2*2log2(3)=a
log8(18)= log2^3(2*3^2)=1/3(log2(2)+2log2(3)=1/3(1+a)
log4(81)=1/2log2(3)^4=4*1/2log2(3)=2a
log8(54)=1/3log2(2*27)=1/3((log2(2)+log2(3^3))=1/3(1+3a)
11у-(3у+12)=4 (2у-3)
11у -3у-12= 8у-12
11у-3у-8у = 12 -12
0у=0