Question

x2 - X-2 = 0 ? me ajudem ​

Answer 1

x² - x - 2 = 0

a = 1

b = -1

c = -2

Δ = b²- 4 . a . c

Δ = (-1)² - 4 . 1 . (-2)

Δ = 1 - (-8)

Δ = 1 + 8

Δ = 9

x = -b ± √Δ /2 . a

x = -(-1) ± √9 /2 . 1

x = 1 ± 3 /2

x' = 1 - 3 /2

x' = -2/2

x' = -1

x" = 1 + 3 /2

x" = 4/2

x" = 2

S = { -1 , 2 }