The rectangle below has an area of k^4-2k^2-8k 4 −2k 2 −8k, start superscript, 4, end superscript, minus, 2, k, squared, minus, 8 square meters and a width of k^2+2k 2 +2k, squared, plus, 2 meters. What expression represents the length of the rectangle? \text{Length} =Length=start text, L, e, n, g, t, h, end text, equals meters