log9 (6√6-15)^2 + log27(6√6+15)^3 = = log3^2 (6√6-15)^2 + log3^3 (6√6+15)^3 = = 1/2* log3 (6√6-15)^2 + 1/3* log3 (6√6+15)^3 = = log3 ((6√6 - 15)^2)^1/2 + log3 ((6√6+15)^3)^1/3 = = log3 | 6√6 - 15 |+ log3 (6√6 +15) = появление модуля (!) = log3 (15 - 6√6) + log3 (15 + 6√6) = = log3 ((15 - 6√6)* (15 + 6√6) ) == log3 (15^2 - (6√6)^2) = = log3 (225 - 216) = = log3 (9) = = 2