Срешением неравенства -2logx/3 27> =log3 27x+1

vadimtolpegin vadimtolpegin    3   26.06.2019 16:50    41

Ответы
annzhoravel461 annzhoravel461  21.07.2020 12:26
-2*3log(x/3) 3≥log(3) 27+log(3) x +1
-6*log(3) 3/log(3) x-log(3) 3≥3+log(3) x +1
log (3) x=t
-6/t-1≥t+4
t+4+6/(t-1)≤0
(t+4)(t-1)+6/t-1≤0
t²+4t-t-4+6/t--1≤0
t²+3t+2/t-1≤0
(t+1)(t+2)/t-1≤0
t≤-2  и  -1≤t<1

log(3) x ≤-2
\left \{ {{x0} \atop {x \leq 3^{-2} }} \right.
\left \{ {{x0} \atop {x \leq \frac{1}{9} }} \right.
0<x≤1/9

-1≤log(3) x <1
1/3≤x<3
ответ x∈(0;1/9]v{1/3;3)
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