In the following monomial, write the constants and variables
\[-\dfrac{7}{9}{{x}^{2}}{{y}^{2}}z\]

Hint: The numerical terms always consider constant and the other terms are known as variables.
The monomial contains only a single term.

Complete step by step answer:

Given monomial is
\[-\dfrac{7}{9}{{x}^{2}}{{y}^{2}}z\]
A monomial is a number, or a variable or the product of a number and one or more variables. ... A linear monomial is an expression which has only one term and whose highest degree is one. It cannot contain any addition or subtraction signs or any negative exponents.
The numerical terms always consider constant and the other terms are known as variables
Therefore
The constants in the monomial is \[-\dfrac{7}{9}\]
The variables in the monomial are \[x,y,z\]

Note:

The degree of the monomial is the sum of the exponents of all included variables. Constants have a monomial degree of 0. A polynomial as opposed to the monomial is a sum of monomials where each monomial is called a term. The degree of the polynomial is the greatest degree of its terms.