Question

Решите уравнение 7х в квадрате +20х-3=0

Answer 1

$7 x^{2} +20x-3=0 \\ D=400+84=484 \\ \sqrt{D} =22 \\ x_{1} = \frac{-20+22}{14} = \frac{2}{14} = \frac{1}{7} \\ \\ x_{2} = \frac{-20-22}{14} =- \frac{42}{14} =-3$