Question

1) Resolva as seguintes equações do 2° grau: ME AJUDEM POR FAVOR!!

A)x² - 5x + 6 = 0
B)x² - 8x + 12 = 0
C)x² + 2x - 8 = 0
D)x² - 4x - 5 = 0
E)y² − 16y + 64 = 0
F)6x² − x − 5 = 0

Answer 1

Resposta:

Usar a fórmula de báskara

a) x² - 5x + 6 = 0

Δ=b²-4a.c

Δ=(-5)²-4.1.6

Δ=25-24

Δ=1

X=-b±√Δ/2.a

X=-(-5)±√1/2.1

X=5±1/2

X₁=5+1/2

X₁=6/2

X₁=3

X₂=5-1/2

X₂=4/2

X₂=2

b) x² - 8x + 12 = 0

Δ=(-8)²-4.1.12

Δ=64-48

Δ=16

X=-b±√Δ/2.a

X=-(-8)±√16/2.1

X=8±4/2

X₁=8+4/2

X₁=12/2

X₁=6

X₂=8-4/2

X₂=4/2

X₂=2

c) x² + 2x - 8 = 0

Δ=2²-4.1.(-8)

Δ=4+32

Δ=36

X=-b±√Δ/2.a

X=-2±√36/2.1

X=-2±6/2

X₁=-2+6/2

X₁=4/2

X₁=2

X₂=-2-6/2

X₂=-8/2

X₂=-4

d) x² - 4x - 5 = 0

Δ=(-4)²-4.1.(-5)

Δ=16+20

Δ=36

X=-b±√Δ/2.a

X=-(-4)±√36/2.1

X=4±6/2

X₁=4+6/2

X₁=10/2

X₁=5

X₂=4-6/2

X₂=-2/2

X₂=-1

e) y² − 16y + 64 = 0

Δ=(-16)²-4.1.64

Δ=256-256

Δ=0

Y=-b±√Δ/2.a

Y=-(-16)±√0/2.1

Y=16±0/2

Y=16/2

Y=8

f) 6x² − x − 5 = 0

Δ=(-1)²-4.6.(-5)

Δ=1+120

Δ=121

X-b±√Δ/2.a

X=-(-1)±√121/2.6

X=1±11/12

X₁=1+11/12

X₁=12/12

X₁=1

X₂=1-11/12

X₂=-10/12

X₂=-5/6