Mister Exam
-2x≥18 inequation
The solution
Detail solution
Given the inequality:
$$- 2 x \geq 18$$
To solve this inequality, we must first solve the corresponding equation:
$$- 2 x = 18$$
Solve:
Given the linear equation:
Divide both parts of the equation by -2
$$x_{1} = -9$$
$$x_{1} = -9$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$-9 + - \frac{1}{10}$$
=
$$- \frac{91}{10}$$
substitute to the expression
$$- 2 x \geq 18$$
$$- \frac{\left(-91\right) 2}{10} \geq 18$$
the solution of our inequality is:
$$x \leq -9$$
$$- 2 x \geq 18$$
To solve this inequality, we must first solve the corresponding equation:
$$- 2 x = 18$$
Solve:
Given the linear equation:
-2*x = 18
Divide both parts of the equation by -2
x = 18 / (-2)
$$x_{1} = -9$$
$$x_{1} = -9$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$-9 + - \frac{1}{10}$$
=
$$- \frac{91}{10}$$
substitute to the expression
$$- 2 x \geq 18$$
$$- \frac{\left(-91\right) 2}{10} \geq 18$$
91/5 >= 18
the solution of our inequality is:
$$x \leq -9$$
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