15-3x>4 inequation

Given the inequality:
$$15 - 3 x > 4$$
To solve this inequality, we must first solve the corresponding equation:
$$15 - 3 x = 4$$
Solve:
Given the linear equation:

15-3*x = 4

Move free summands (without x)
from left part to right part, we given:
$$- 3 x = -11$$
Divide both parts of the equation by -3

x = -11 / (-3)

$$x_{1} = \frac{11}{3}$$
$$x_{1} = \frac{11}{3}$$
This roots
$$x_{1} = \frac{11}{3}$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$- \frac{1}{10} + \frac{11}{3}$$
=
$$\frac{107}{30}$$
substitute to the expression
$$15 - 3 x > 4$$
$$15 - \frac{3 \cdot 107}{30} > 4$$

43    
-- > 4
10    

the solution of our inequality is:
$$x < \frac{11}{3}$$

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