A monomial is a number, a variable, or a product of a number and one or more variables.
The only rules are that the variables should be raised to only positive integer powers (no square roots or 1/ x 's allowed), and no plus or minus signs.
17, 4 2 , 3 xy , -4 x 2 , xyz , 6 p 5 q 3 r
When you multiply monomials, first multiply the coefficients and then multiply the variables by adding the exponents.
Note that when you multiply monomials with same base, you can add their exponents.
This is called the Product of Powers Property.