x^{2} + b \cdot x + c = {(x + \frac{b}{2})}^{2} - \frac{b^{2}}{4} + c

${x^2 + b \cdot x + c = {\left (x + \frac {b} {2} \right)}^2 - \frac {b^2} {4} + c}$

Error