Express the given set in interval notation and graph.
$\{$$x$ $\mid$$x\le 7$$\}$

• A. (−∞,7]
• B. [−∞,7]
• C. (−∞,7)
• D. [7, ∞)

Answer: (A)

Verified step by step guidance

1. Identify the inequality given in the set notation: \( x \leq 7 \). This means all numbers less than or equal to 7 are included in the set.
2. In interval notation, a square bracket \([\) is used to denote that the endpoint is included, while a parenthesis \(()\) is used to denote that the endpoint is not included.
3. Since the inequality is \( x \leq 7 \), the number 7 is included in the set. Therefore, we use a square bracket at 7.
4. The set includes all numbers less than 7, extending indefinitely to the left. This is represented by \(-\infty\) in interval notation, which always uses a parenthesis because infinity is not a specific number that can be reached.
5. Combine these observations to express the set in interval notation: \((-\infty, 7]\).