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Decades: 690s BC 680s BC 670s BC 660s BC 650s BC - 640s BC - 630s BC 620s BC 610s BC 600s BC 590s BC
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... 4a2. 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 ...