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log(x^3-9*x^2+27*x-27)*(9-x)>=0 inequation

A inequation with variable

The solution

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log\x  - 9*x  + 27*x - 27/*(9 - x) >= 0
$$\left(9 - x\right) \log{\left(\left(27 x + \left(x^{3} - 9 x^{2}\right)\right) - 27 \right)} \geq 0$$
(9 - x)*log(27*x + x^3 - 9*x^2 - 27) >= 0
Detail solution
Given the inequality:
$$\left(9 - x\right) \log{\left(\left(27 x + \left(x^{3} - 9 x^{2}\right)\right) - 27 \right)} \geq 0$$
To solve this inequality, we must first solve the corresponding equation:
$$\left(9 - x\right) \log{\left(\left(27 x + \left(x^{3} - 9 x^{2}\right)\right) - 27 \right)} = 0$$
Solve:
$$x_{1} = 9$$
$$x_{1} = 9$$
This roots
$$x_{1} = 9$$
is the points with change the sign of the inequality expression.
First define with the sign to the leftmost point:
$$x_{0} \leq x_{1}$$
For example, let's take the point
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$- \frac{1}{10} + 9$$
=
$$\frac{89}{10}$$
substitute to the expression
$$\left(9 - x\right) \log{\left(\left(27 x + \left(x^{3} - 9 x^{2}\right)\right) - 27 \right)} \geq 0$$
$$\left(9 - \frac{89}{10}\right) \log{\left(-27 + \left(\left(- 9 \left(\frac{89}{10}\right)^{2} + \left(\frac{89}{10}\right)^{3}\right) + \frac{27 \cdot 89}{10}\right) \right)} \geq 0$$
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log|------|     
   \ 1000 / >= 0
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     10         

the solution of our inequality is:
$$x \leq 9$$
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Solving inequality on a graph
Rapid solution 2 [src]
[4, 9]
$$x\ in\ \left[4, 9\right]$$
x in Interval(4, 9)
Rapid solution [src]
And(4 <= x, x <= 9)
$$4 \leq x \wedge x \leq 9$$
(4 <= x)∧(x <= 9)