I found this online, hope it helps
Just follow these steps:
Multiply normally, ignoring the decimal points.
Then put the decimal point in the answer - it will have as many decimal places as the two original numbers combined.
A polynomial is the sum of at least one term. For example, x^3+1 is a polynomial. A monomial is a polynomial with only one term, such as 2x^2.
A binomial is a polynomial with two terms, and a trinomial is one with three terms. The example you gave is a trinomial (which is also a polynomial).
Degree of a polynomial is the largest sum of variable powers in any term of the polynomial. So, for example, x^2 y has degree 3, and x^3+x^2 also has degree 3. A sixth degree polynomial would be x^6-2x+1, for example.
The answer is B because it is at -4 then increases 4 so now it is 0 degrees .