Solve x2 - 7x = -13
\(x^{2}-7x=-13 \\ \\ x^{2}-7x+13=0 \\ \\ \Delta=(-7)^{2}-4*1*13=49-52=-3 \implies x ot\in R \\ \\ \sqrt{\Delta} =i \sqrt{3} \\ \\ x_{1}= \frac{7-i \sqrt{3} }{2} \\ \\ x_{2}= \frac{7+i \sqrt{3} }{2}\)
