Question

$x2 -4x -5 =0$

Answer 1

$- 2x = 5$
$x = - \frac{2}{5}$

Answer 2

${x}^{2} - 4x - 5 = 0$

a = 1

b = - 4

c = - 5


∆ = (-4)^2 - 4 . 1 . (-5)

∆ = 16 + 20

∆ = 36

∆ =√36

∆ = 6



X ' = 4 + 6 / 2

X ' = 10 / 2

X ' = 5


X " = 4 - 6 / 2

X " = - 2 / 2

X " = - 1





S = { 5 , - 1 }