The word 'everything' is not a noun.The word 'everything' is a pronoun, a word that takes the place of a noun in a sentence.The pronoun 'everything' is an indefinite pronoun a word that takes the place of an unknown or unnamed number of things.
Letter
A letter used to represent a number is a variable of sometimes a constant.
Coefficients are the numbers directly in front of a variable. Variables are letters in place of numbers in a mathematical problem . For example the expression, "2x" has a variable and a coefficient. The variable is the letter x, and the coefficient is the number 2. The coefficient is NEVER a letter, and is always a number. Coefficients and variables can be used in both scientific and algebraic expressions.
Usually the letter n stands for number, and it means some unspecified number.
A variable
Yes, it can be.
A variable.
The unknown or the variable
They are variables or unknowns and are used in algebra.
In Latin there were letters instead of our kind of numbers: I = 1 V =5 X = 10 L = 50 C = 100 and so on.
T in the metric unit of weight is ton.
Yes, it is.
The gender of the pronoun 'it' is neuter, a word that takes the place of a noun for a thing that has no gender.The number of the pronoun 'it' is singular, a word that takes the place of a noun for one thing.
variable
variable
When you do not know the value of a particular number, the most usual symbol used in place of that number is the letter x.