Given the inequality:
$$2^{4 - 3 x} + 8^{x} > 17$$
To solve this inequality, we must first solve the corresponding equation:
$$2^{4 - 3 x} + 8^{x} = 17$$
Solve:
Given the equation:
$$2^{4 - 3 x} + 8^{x} = 17$$
or
$$\left(2^{4 - 3 x} + 8^{x}\right) - 17 = 0$$
Do replacement
$$v = \left(\frac{1}{8}\right)^{x}$$
we get
$$2^{4 - 3 x} - 17 + \frac{1}{v} = 0$$
or
$$2^{4 - 3 x} - 17 + \frac{1}{v} = 0$$
do backward replacement
$$\left(\frac{1}{8}\right)^{x} = v$$
or
$$x = - \frac{\log{\left(v \right)}}{\log{\left(8 \right)}}$$
$$x_{1} = 0$$
$$x_{2} = \frac{4}{3}$$
$$x_{3} = - \frac{2 i \pi}{3 \log{\left(2 \right)}}$$
$$x_{4} = \frac{2 i \pi}{3 \log{\left(2 \right)}}$$
$$x_{5} = \frac{4}{3} - \frac{2 i \pi}{3 \log{\left(2 \right)}}$$
$$x_{6} = \frac{4}{3} + \frac{2 i \pi}{3 \log{\left(2 \right)}}$$
Exclude the complex solutions:
$$x_{1} = 0$$
$$x_{2} = \frac{4}{3}$$
This roots
$$x_{1} = 0$$
$$x_{2} = \frac{4}{3}$$
is the points with change the sign of the inequality expression.
First define with the sign to the leftmost point:
$$x_{0} < x_{1}$$
For example, let's take the point
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$- \frac{1}{10}$$
=
$$- \frac{1}{10}$$
substitute to the expression
$$2^{4 - 3 x} + 8^{x} > 17$$
$$\frac{1}{\sqrt[10]{8}} + 2^{4 - \frac{\left(-1\right) 3}{10}} > 17$$
7/10
2 3/10
----- + 16*2 > 17
2
one of the solutions of our inequality is:
$$x < 0$$
_____ _____
\ /
-------ο-------ο-------
x1 x2Other solutions will get with the changeover to the next point
etc.
The answer:
$$x < 0$$
$$x > \frac{4}{3}$$