The standard form of a polynomial is the descending order, that means that it must be written according from its higher power, down straight to the coefficient with no variable.
Hence, the leading coefficient is the one that is next to the highest exponent of the polynomial, in this case: =3x2.
5 is a whole number so keep it as 5 then 4 is in the tenths place so that means have ten for the denominator so 5 and 4/10 is the mixed number then simplified to 5 and 2/5