Answer:
second degree monomial
Step-by-step explanation:
5x^2
This has one term, so it is a monomial
The term has a power of 2 so it is a quadratic ( second degree)
quadratic monomial
the degree of a polynomial comes from degree of its highest term, and each term gets their degree from the sum of its variables' exponents.
5x² <---- just one=MONO, term, a monomial
that term has one variable "x", and it has an exponent of "2", so 2nd degree.