Question 253266
I agree the second answer is right.
multiply by a  and  you get  3a^4 + 4a^3 - a^2 - a
multiply by (-5) and you get    -15 a^3 - 20 a^2 + 5a + 5
giving 3a^4 + (4-15)a^3 -(20 + 1)a^2 + (5 - 1)a +5