Mister Exam
−4x≥28 inequation
The solution
Detail solution
Given the inequality:
$$- 4 x \geq 28$$
To solve this inequality, we must first solve the corresponding equation:
$$- 4 x = 28$$
Solve:
Given the linear equation:
Divide both parts of the equation by -4
$$x_{1} = -7$$
$$x_{1} = -7$$
This roots
$$x_{1} = -7$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$-7 + - \frac{1}{10}$$
=
$$- \frac{71}{10}$$
substitute to the expression
$$- 4 x \geq 28$$
$$- \frac{\left(-71\right) 4}{10} \geq 28$$
the solution of our inequality is:
$$x \leq -7$$
$$- 4 x \geq 28$$
To solve this inequality, we must first solve the corresponding equation:
$$- 4 x = 28$$
Solve:
Given the linear equation:
-4*x = 28
Divide both parts of the equation by -4
x = 28 / (-4)
$$x_{1} = -7$$
$$x_{1} = -7$$
This roots
$$x_{1} = -7$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$-7 + - \frac{1}{10}$$
=
$$- \frac{71}{10}$$
substitute to the expression
$$- 4 x \geq 28$$
$$- \frac{\left(-71\right) 4}{10} \geq 28$$
142/5 >= 28
the solution of our inequality is:
$$x \leq -7$$
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