What is the leading coefficient of this polynomial expression?

The leading term is 4x^2, which is the term with the largest exponent. The leading coefficient is the coefficient of the leading term. Basically it's the first number you read assuming the terms are sorted in the proper order of exponents counting down. For something like x^2+10x+5, the leading coefficient is 1 because x^2 is the same as 1x^2.

4x and 6y

im not sure though