Question

найдите корни уравнения 4х^2+19х-5=0

Answer 1

 

$<var>4x^2+19x-5 = 0\\\\ D = 19^2+4*4*5 = 361+80 = 441\\\\ x_1 = \frac{-19+\sqrt{441}}{8} = \frac{-19+21}{8} = \frac{1}{4}\\\\ x_1 = \frac{-19-\sqrt{441}}{8} = \frac{-19-21}{8} = -\frac{40}{8} = -5\\\\ \fbox{x = 0.25, x = -5}</var>$

 

Answer 2

4х^2+19х -5 =0

D=361-4*4*(-5)=361+80=441

441 это корень из  21

x1,2=(-19+-21)/8

x1 = -5                     x2=0.25

Ответ: -5;  0.25