Final answer:
The degree of the polynomial is 6 and the leading coefficient is 7.
Step-by-step explanation:
The given expression is 18−3y+5y^2−y^5+7y^6.
The degree of a polynomial is determined by the term with the highest exponent. In this case, the term with the highest exponent is 7y^6, so the degree of the polynomial is 6.
The leading coefficient is the coefficient of the term with the highest degree. In this case, the term with the highest degree is 7y^6, so the leading coefficient is 7.