<span>log9 (6√6-15)^2 + log27(6√6+15)^3 =
= </span>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
3х^2+12х-х-4=0
3х2+11х-4=0
Д=169
х1=1/3
х2=-4
<span>3a * (a+b-c) - 3b (a-b-c) + 3c (a-b+c)=3a</span>²+3ab-3ac-3ab+3b²+3bc+3ac-3bc+3c²=3a²+3b²+3c²