<span>(12d</span>⁴<span>-7)</span>²=(12d⁴)²-2*12d⁴*7+7²=144d⁸-168d⁴+49
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log9 3^(5x - 5) = 4
log9 9^ ((5x-5)/2) = log9 9^4
(5x - 5)/2 = 4
5x - 5 = 8
5x = 13
x = 13/5
x = 2,6
Ответ. 2,6
ОДЗ
{ x < 5
{ x < ∛35 ≈ 3,27 => x < ∛35
lg (35 - x^3) = lg (5 - x)^3
35 - x^3 = (5 - x)^3
35 - x^3 - (5 - x)^3 = 0
35 - x^3 + (x - 5)^3 = 0
35 - x^3 + (x^3 - 15x^2 + 75x - 125) = 0
- 15x^2 + 75x - 90 = 0
15x^2 - 75x + 90 = 0 /:15
x^2 - 5x + 6 = 0
D = 1
x1 = 2 ∈ ОДЗ
x2 = 3 ∈ ОДЗ
Ответ
2; 3