Do you understand what "degree" means? A polynomial is of degree "n" if and only if the highest power in the polynomial is n (I bet you learned that long ago!).

4- 1(x- 8) is wrong because it is of degree 1, not 2.

is wrong because it is of degree 2, not 3.

You seem be thinking that "degree" is the number of terms in the polynomial- it isn't. A polynomial of degree n typically has n+1 terms.