Centuries: 1st century - 2nd century - 3rd century
Decades: 120s 130s 140s 150s 160s - 170s - 180s 190s 200s 210s 220s
Years: 169 170 171 172 173 - 174 - 175 176 177 178 179
Births
Deaths
... We get <math>\left(x+\frac{b}{2a}\right)^2=\frac{-4ac+b^2}{4a^2}=\frac{b^2-4ac}{4a^2}.</math> Taking square roots of bo ...