Help I’m so confused

Answer:
5x: linear; monomial
-7: constant; monomial
x^2 + 4: quadratic, binomial
x^2 - 3x + 11: quadratic, trinomial
2x - 9: linear, binomial
Step-by-step explanation:
Name using degree: just count the highest number of variables in a single term. if it's 0, its a constant polynomial, if it's 1 it's linear, 2 quadratic, 3 cubic
Name using number of terms: just count the number of "things" added or subtracted. If there's one, it's a monomial, two: binomial, three: trinomial.