Question

What are the solutions to x^2-13x+30

Answer 1

$ax^2+bx+c=0 \\ \\ x^2-13x+30 = 0 \\ \\ D=b^2-4ac = 169-120=\sqrt{49} =7 \\ \\ x_{1/2} = \frac{-b^2+/-\sqrt{D}}{2a} = \frac{13+/-7}{2*1} \\ \\ x_1 = \frac{13+7}{2} = 10 \\ \\ x_2 = \frac{13-7}{2} = 3$