is a monomial an expresion that dose not use addition and subtraction

http://www.mathwords.com/m/monomial.htm

No, a monomial can use addition and subtraction.

A monomial is a mathematical expression that consists of a single term. A term is a combination of a coefficient and one or more variables raised to non-negative integer exponents.

For example, "5x" is a monomial because it has a single term with a coefficient of 5 and a variable "x" raised to the first power.

Similarly, "3y^2 + 2xy" is also a monomial because it can be simplified to a single term by combining like terms ("3y^2" and "2xy") with the coefficients of 3 and 2.

So, monomials can involve both addition and subtraction, as long as they have a single term.