a) degree: 4
descending order: 11x^4 - 4x^2 - 12
b) degree: 5
descending order: 2x^5 - 3x^4 + 3x^3 + 7x + 14
let's start with a. in descending order, the exponents of the polynomial go down with each term. the term with the largest exponent is 11x^4, so this goes first. next is -4x^2, so this goes 2nd. last is -12. so, we have 11x^4 - 4x^2 - 12. to find the degree, it's just the largest exponent, so it is 4.
now for b. the largest exponent is 5, so the degree is 5, and that term is 2x^5, so this will go first. keep on looking for the next highest exponent untill you get down to 14, so the answer is 2x^5 - 3x^4 + 3x^3 + 7x + 14.
x^2 + 16^2 = (x + 8)^2
x^2 + 256 = x^2 + 16*x + 64
256 = 16*x + 64
192 = 16*x
x = 12
answer d is correct.