Question

Calcule X²-9x+18=0. Por favor me ajudem

Answer 1

x² - 9x + 18 = 0

Δ = (-9)² - 4(1)(18)
Δ = 81 - 72
Δ = 9

$x = \frac{9~\pm~3}{2} \\ \\ x' = 6 \\ \\ x'' = 3$


S = {3, 6}

Answer 2

x² - 9x + 18 = 0
a = 1, b = - 9, c = 18

Δ = b² - 4ac
Δ = (- 9)² - 4 . 1 . 18
Δ = 81 - 72
Δ = 9 = 3²

x = (- b ± √Δ)/2a
x = (- (- 9) ± √3²)/2 . 1
x = (9 ± 3)/2
x = 4,5 ± 1,5

x' = 4,5 + 1,5 = 6
x'' = 4,5 - 1,5 = 3

S = {6, 3}