Respuesta :

[5, +∞) ∪ (-∞,7] is the notation to express the set of all numbers greater than or equal to 5 and less than or equal to 7​.

We need to use interval notation to express the set of all numbers greater than or equal to 5 and less than or equal to 7​.

What is a set?

A set is a mathematical model for a collection of different things; a set contains elements or members, which can be mathematical objects of any kind: numbers, symbols, points in space, lines, other geometrical shapes, variables, or even other sets.

Let x belong to the set of real numbers (R)

Now, x≥5 and x≤7.

So, x≥5⇒[5, +∞) and x≤7⇒(-∞,7]

Therefore, the notation will be [5, +∞) ∪ (-∞,7].

To learn more about sets visit:

https://brainly.com/question/8053622.

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