2017-05-25-154458.ipynb

Kernel: SageMath 7.6

x, b, c = var('x b c')
solve([x^2 + b*x + c == 0],x)

[x == -1/2*b - 1/2*sqrt(b^2 - 4*c), x == -1/2*b + 1/2*sqrt(b^2 - 4*c)]