Centuries: 1st century - 2nd century - 3rd century
Decades: 130s 140s 150s 160s 170s - 180s - 190s 200s 210s 220s 230s
Years: 178 179 180 181 182 - 183 - 184 185 186 187 188
Births
Deaths
... of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = b/(2a), so we add the square of b/(2a) to both sides, ...