Which compound inequality does the number line represent?

A. [tex]-4x \geq 12[/tex] and [tex]-4x \ \textless \ -8[/tex]

B. [tex]-13 \leq 4x - 1 \ \textless \ 7[/tex]

C. [tex]2x \leq -6[/tex] or [tex]2x \geq 4[/tex]

D. [tex]5x \geq -15[/tex] or [tex]5x \ \textless \ 10[/tex]



Answer :

To determine which compound inequality the number line represents, we need to systematically check each given option to see if the inequalities are valid and consistent within the option.

1. For the inequality [tex]\(-4x \geq 12\)[/tex] and [tex]\(-4x < -8\)[/tex]:
- For [tex]\(-4x \geq 12\)[/tex]:
[tex]\[ -4x \geq 12 \implies x \leq -3 \][/tex]
- For [tex]\(-4x < -8\)[/tex]:
[tex]\[ -4x < -8 \implies x > 2 \][/tex]
- Combining these:
[tex]\[ \begin{cases} x \leq -3 \\ x > 2 \end{cases} \][/tex]
These two conditions cannot be true simultaneously because no number can be both less than or equal to [tex]\(-3\)[/tex] and greater than [tex]\(2\)[/tex] at the same time. Therefore, this compound inequality is invalid.

2. For the inequality [tex]\(-13 \leq 4x - 1 < 7\)[/tex]:
- First inequality [tex]\(-13 \leq 4x - 1\)[/tex]:
[tex]\[ -13 \leq 4x - 1 \implies -12 \leq 4x \implies -3 \leq x \][/tex]
- Second inequality [tex]\(4x - 1 < 7\)[/tex]:
[tex]\[ 4x - 1 < 7 \implies 4x < 8 \implies x < 2 \][/tex]
- Combining these:
[tex]\[ -3 \leq x < 2 \][/tex]
This is a valid compound inequality since [tex]\(x\)[/tex] can satisfy both conditions simultaneously.

3. For the inequality [tex]\(2x \leq -6\)[/tex] or [tex]\(2x \geq 4\)[/tex]:
- First inequality [tex]\(2x \leq -6\)[/tex]:
[tex]\[ 2x \leq -6 \implies x \leq -3 \][/tex]
- Second inequality [tex]\(2x \geq 4\)[/tex]:
[tex]\[ 2x \geq 4 \implies x \geq 2 \][/tex]
- The compound inequality is:
[tex]\[ x \leq -3 \quad \text{or} \quad x \geq 2 \][/tex]
This is valid because it specifies [tex]\(x\)[/tex] being in two distinct regions on the number line.

4. For the inequality [tex]\(5x \geq -15\)[/tex] or [tex]\(5x < 10\)[/tex]:
- First inequality [tex]\(5x \geq -15\)[/tex]:
[tex]\[ 5x \geq -15 \implies x \geq -3 \][/tex]
- Second inequality [tex]\(5x < 10\)[/tex]:
[tex]\[ 5x < 10 \implies x < 2 \][/tex]
- The compound inequality:
[tex]\[ x \geq -3 \quad \text{or} \quad x < 2 \][/tex]
This is valid because it doesn't exclude any range of [tex]\(x\)[/tex].

Upon reviewing the options, the compound inequalities are:

- [tex]\(-4 x \geq 12\)[/tex] and [tex]\(-4 x < -8\)[/tex]: Invalid
- [tex]\(-13 \leq 4 x -1 < 7\)[/tex]: Valid
- [tex]\(2 x \leq -6\)[/tex] or [tex]\(2 x \geq 4\)[/tex]: Valid
- [tex]\(5 x \geq -15\)[/tex] or [tex]\(5 x < 10\)[/tex]: Valid

Since the number line can represent the inequalities [tex]\(\{-3 \leq x < 2\}\)[/tex], [tex]\(\{x \leq -3\)[/tex] or [tex]\(\{x \geq 2\}\)[/tex], and [tex]\(\{x \geq -3\)[/tex] or [tex]\(\{x < 2\}\)[/tex], but considering which one best fits a compound inequality structure, we conclude:

The compound inequality most likely represented is:
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