Given the following question:
(incomplete question)
To determine the degree of a polynomial we have to find the highest power IN the polynomial.
Example:

Since 6 is the highest power in the polynomial.
To find the leading coefficient of a polynomial is the first coefficient (number placed before a variable) in the polynomial.
Example one:

Since 4 is the first coefficient in the polynomial.
Example two:

Since 3 is the first coefficient in the polynomial.