Question

which of the following polynomials has degree 4 3 terms and 2 variables

Answer 1

Variables are letters. A polynomial with two lettets, such as x and y, or a and b, has 2 variables. For example, 2x + 3y, or 2a^ + ab - 5b^2
The terms are added or subtracted. That's how you count them. Above, the first example has 2 terms and the second one has 3.
The degree of a term is the sum of the exponents of all variables in the term.
Remember that a plain variable, such as x, has degree 1, not zero.
The degree of a polynomial is the same as the degree of the term with highest degree.