Question

Calcule as Equações Do 2 Grau
a) x² + 9x+8=0
b)9x² - 24x + 16 = 0

Answer 1

a) x² + 9x + 8 = 0
a=1 b=9 c=8

Δ = b² - 4 . a . c
Δ = 9² - 4 . 1 . 8
Δ = 81 - 32
Δ = 49

X = - b +/- √Δ / 2 . a
X = -9 +/- √49 / 2.1
X = -9 +/- 7 / 2

X1 = -9 + 7 / 2 = -2 / 2 = 1

X2= -9 - 7 / 2 = -16 / 2 = -8

Ou seja X1 vale 1 e X2 vale -8.

b) 9x² - 24x + 16 = 0
a=9 b=-24 c=16

Δ = b² - 4 . a . c
Δ = -24² - 4 . 9 . 16
Δ = 576 - 576
Δ = 0

X = - b +/- √Δ / 2 . a
X = - (-24) +/- √0 / 2 . 9
X = 24 +/- 0 / 18

X1 = 24 + 0 / 18 = 24 / 18 = 1,33

X2 = 24 - 0 / 18 = 24 / 18 = 1,33

Ou seja X1 e X2 vale 1,33.

Answer 2

a) a= 1 b=9 c=8
Então calculamos: Delta= b²-4*a*cc Delta= 9²- 4*1*8
Delta= 81- 32
Delta= 49
X=-9 ± √49/2*1
X= -9± 7/2 X¹= -9+7/2= -2/2: -1
X²= -9-7/2= -16/2= -8.
b)a=9 b=-24 c=16
Delta= (-24)²-4*9*16
Delta= 576 +576
Delta=1.152 X:24±√1.152/ 2*9
X: 24±1.07/18
X¹:25.07/18:1.392 X²:22.93/18:1.273