Answer: 3
Step-by-step explanation:
The equation y = 5x^2+3x^6-10x-8 is not in standard form.
Why not? Because the term with the largest exponent (6) isn't listed first.
The standard form would be y = 3x^6+5x^2-10x-8; note the exponents decrease (6, 2, 1, then 0).
After the polynomial is in standard form, we can read off the leading coefficient to be 3. This is the coefficient of the first term 3x^6.
Side note: The degree is 6 as it's the largest exponent.