Answer:
a) 12
Step-by-step explanation:
The degree of a monomial is calculated by adding up all of the exponents of it different components, including the implicit degrees of the terms, when a exponent is not shown it is implicit that that exponent is 1, so in this case we have as exponents 3 and 9, after adding them up we get 12, so the degree of the monomial would be 12