Use inequality notation and interval notation to describe y is no more than 20

Question

asked Aug 21, 2019 117k views

2 Answers

Raspy · Answer 1 · 2019-08-23T20:47:07+0000

Answer:

Inequality notation:
$y\leq 20$

Interval notation: ( - ∞, 20]

Explanation:

"y is no more than 20"

means y is NOT larger than 20, but less than AND also equal to 20.

This can be written with inequality sign as
$y\leq20$

In interval notation,

We use "(" or ")" sign to mean inequality ONLY ( "<" or ">" )
When we want to include EQUALS TO with "<" or ">", then we use "[" or "]" sign.

So
$y\leq20$ would mean that y is from -∞ till 20, where 20 is INCLUDED.

Hence, we can write (-∞,20] in interval notation.

Note:

The "(" before -∞ indicates that it is not included (infinity is not a number, but a concept so you can't equate something to infinity)

The "]" after 20 indicates that 20 is INCLUDED in the inequality

Mathias Falkenberg · Answer 2 · 2019-08-26T14:21:00+0000

Answer:

Inequality Notation:
$y\leq 20$

Interval Notation:
$(-\infty , 20]$

Explanation:

Inequality Notation: It is like an equation that uses symbols for :

*Less than - '<'

* Less than or equal to - '
$\leq$ '

*Greater than - ' >'

* Greater than or equal to -
$'\geq '$

and Equal to - '='

Interval Notation: In this we just write the beginning and ending numbers of the interval, and we use:

* [ ] - Square bracket when we want to include the end value, or

* ( ) - Round bracket when we don't include the value.

To describe y is no more than 20.

As no more than means no greater than or not above.

then, y is no more than 20 which implies
$y\leq 20$

Therefore, the Interval notation for y is no more than 20 is ;
$(-\infty , 20]$ and the inequality notation is;
$y\leq 20$