What is a variable, how to declare a variable, and rules for variables including arbitrary variables

1. Variable Definition
● A number or a symbol used to represent an unknown
value
● Use letters of the alphabet such as x, y, z
● The letter i is reserved for an imaginary number, so we
don’t use i as a variable
● The letter e is also reserved for Euler’s constant
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2. Variable Tips for a known object or thing or person
● If a person, place, object is know, then we use the first
letter of the person, place, or object for the variable
● Otherwise, we must pick an arbitrary variable
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3. Variable Examples for Person, place, or thing
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Example Variable
John’s age a
Mary’s height h
strawberries s
eggs e
cars c
dimes d

4. Variable Examples for unknown things
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Example Variable
A number x
An unknown number x
Some number x
A number and another different number x, y

5. Variable calculator
https://www.mathcelebrity.com/calculator.php
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