Question

Реши квадратное уравнение 4x2−21x+5=0.

Корни: x1 =
x2 =

Answer 1

Ответ:

$d = 441 - 4 \times 4 \times 5 = 441 - 80 = \\ = 361 = {19}^{2} \\ x1 = \frac{21 + 19}{8} = \frac{40}{8} = 5$

$x2 = \frac{21 - 19}{8} = \frac{2}{8} = \frac{1}{4}$

Answer 2

4x^2-21x+5=0

d=441-4*4*5=441-80=361 √361=19

x1,2=(21+-19)/2*4=5;0,25.