Mister Exam

(4x−1)\9≥1 inequation

A inequation with variable

The solution

You have entered [src]
4*x - 1     
------- >= 1
   9        
$$\frac{4 x - 1}{9} \geq 1$$
(4*x - 1)/9 >= 1
Detail solution
Given the inequality:
$$\frac{4 x - 1}{9} \geq 1$$
To solve this inequality, we must first solve the corresponding equation:
$$\frac{4 x - 1}{9} = 1$$
Solve:
Given the linear equation:
(4*x-1)/9 = 1

Expand brackets in the left part
4*x/9-1/9 = 1

Move free summands (without x)
from left part to right part, we given:
$$\frac{4 x}{9} = \frac{10}{9}$$
Divide both parts of the equation by 4/9
x = 10/9 / (4/9)

$$x_{1} = \frac{5}{2}$$
$$x_{1} = \frac{5}{2}$$
This roots
$$x_{1} = \frac{5}{2}$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$- \frac{1}{10} + \frac{5}{2}$$
=
$$\frac{12}{5}$$
substitute to the expression
$$\frac{4 x - 1}{9} \geq 1$$
$$\frac{-1 + \frac{4 \cdot 12}{5}}{9} \geq 1$$
43     
-- >= 1
45     

but
43    
-- < 1
45    

Then
$$x \leq \frac{5}{2}$$
no execute
the solution of our inequality is:
$$x \geq \frac{5}{2}$$
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       x1
Solving inequality on a graph
Rapid solution [src]
And(5/2 <= x, x < oo)
$$\frac{5}{2} \leq x \wedge x < \infty$$
(5/2 <= x)∧(x < oo)
Rapid solution 2 [src]
[5/2, oo)
$$x\ in\ \left[\frac{5}{2}, \infty\right)$$
x in Interval(5/2, oo)