How do you define a variable and write an expression for each phrase: nine times the quotient of a number and three?
In algebra we can work with numbers even if we do not know their exact value.
WE can always just call a number
This is called defining the variable.
In this question where a number is being referred to, let's call the number "x".
Let the number be
The word "quotient" means the answer to a division and is always used with the word "AND".
The QUOTIENT of
"nine times the quotient of a number and three" means
Muliply 9 by the answer to our number (x), divided by 3.