If ABCD is a parallelogram, we have to prove that slope of
AB = CD and slope of BC = DA. Using the formula m = (y1-y2) / (x1-x2), the
slope of line segment AB = 0/-4, CD =
0/-4, BC = 1, DA = 1. Going back to the
condition, the slope we get for each line segment proves that ABCD is a
parallelogram.
The polynomial is a third degree polynomial with x and y terms so when written in standard form x comes before y and the x^3 is going to be the first term. The first term of this polynomial is 8x^3, aka the second answer choice.
