1) log a B= 1/log b A
2) log a^k B = log a B/k = 1/k * log a B( 1/k, умноженная на log a B)
log 2 18= log 2 (2*9)=log 2 2 + log 2 9= 1+log 2 9
из 1)
log 36 2 = 1/ log 2 36 = 1/ log 2 (4*9)= 1/(log 2 4+log 2 9)=1/(2+log 2 9)
log 2 18/log 36 2 =(1+log 2 9)*(2+log 2 9)=2 +log 2 9+3 log 2 9 + (log 2 9)^2
из 1)
log 72 2 = 1/ log 2 72 = 1/log 2 (8*9)=1/(log 2 8+log 2 9)=1/(3+log 2 9)
log 2 9/log 72 2 = log 2 9 *(3+log 2 9)= 3 log 2 9 + (log 2 9)^2
log 2 18/log 36 2 - log 2 9/log 72 2 = 2 +log 2 9+3 log 2 9 + (log 2 9)^2 - -(3 log 2 9 + (log 2 9)^2) = 2 +log 2 9+3 log 2 9 - 3 log 2 9 - (log 2 9)^2 =2
Ответ: вариант А) 2