#### Answer

leading term: $-8x^6$

#### Work Step by Step

The leading term of a polynomial is the term with the highest degree.
The terms of the given polynomial have the following degrees:
$x^2$ - degree is 2
$-10$ - degree is 0
$5x$ - degree is 1
$-8x^6$ - degree is 6
Notice that the term with the highest degree is $-8x^6$ with a degree of $6$.
Thus, the leading term of the given polynomial is: $-8x^6$.