1) 5log b^2/a (a^2/b); если log a (b)=3 log a (a^2/b) log a (a^2) - log a (b)5log (b^2)/a (a^2/b)= 5· ------------------ = 5· --------------------------- = log a (b^2)/a log a (b^2)-log a (a) 2- 3 (-1)= 5 --------- = 5 ---- = -1 2·3 -1 52) log 2 (a^1/3) , если log 4 (a^3)=9log 4 (a^3)=9 ⇔3 log 4 (a)=9 ⇔ log 4 (a)=3 log 4 (a^1/3) (1/3)log 4 (a) 1log 2 (a^1/3) = ---------------- = ----------------- = ------ = 2 log 4 (2) log 4 (√4) 1/23) lg2.5 если log 4(125) = alog 4(125) = a ⇔ log 4(5³) =3 log 4(5) =a ⇔ log 4(5)=a/3 log 4 (5/2) log 4 (5)-log 4 (2) a/3-1/2 2a-3lg2.5 =-------------- = ------------------------- = ----------- = --------- log 4 (5·2) log 4 (5) +log 4 (2) a/3 +1/2 2a+3