Answer:
-5
Explanation:
In a polynomial, the coefficient of the term with the highest degree or power is called the leading coefficient of the polynomial.
We are given a polynomial
. It is a good idea to rearrange this polynomial with powers in a descending order.

As we can see the highest power being 7 so the coefficient of the term with the power 7 is -5. Therefore, -5 is the leading coefficient.