Answer
7
Work Step by Step
When the terms are written in order, the polynomial can be written as:
$$x^7+9x^4+x^2-12$$
Thus, in order, we see that (a) the degree of each term is 7, 4, 2, 0; (b) the leading term is $x^7$ with a coefficient of 1; and (c) the degree of the polynomial is 7.