Question

Usando as fórmulas do Delta e do Bhaskara resolva as equações do 2° grau completa

a) x- 2x -8 = 0

b) x - 3x -4 = 0

c) X - 8x + 7 = 0

d) 3x - 7x + 4 = 0

e) 5x + 3x + 5 = 0​

Answer 1

Resposta:

a)x²- 2x -8 = 0

a=1

b=-2

c=-8

Δ=b²-4.a.c

Δ=(-2)²-4.1.(-8)

Δ=4+32

Δ=36

x=-b±√Δ/2

x=-(-2)±√36/2

x=2±6/2

x1=2+6/2

x1=8/2

x1=4

x2=2-6/2

x2=4/2

x2=2

b)x² - 3x -4 = 0

a=1

b=-3

c=-4

Δ=b²-4.a.c

Δ=(-3)²-4.1.(-4)

Δ=9+16

Δ=25

x=-b±√Δ/2

x=-(-3)±√Δ/2

x=3±√25/2

x=3±5/2

x1=3+5/2

x1=8/2

x1=4

x2=3-5/2

x2=2/2

x2=1

c) X ²- 8x + 7 = 0

α=1

β=-8

c=7

Δ=b²-4.a.c

Δ=(-8)²-4.1.7

Δ=64-28

Δ=36

x=-b±√Δ/2

x=-(-8)±√36/2

x=8±6/2

x1=8+6/2

x1=14/2

x1=7

x2=8-6/2

x2=2/2

x2=1

d) 3x² - 7x + 4 = 0

a=3

b=-7

c=4

Δ=b²-4.a.c

Δ=(-7)²-4.3.4

Δ=49-48

Δ=1

x=-b±√Δ/2

x=-(-7)±√1/2

x=7±1/2

x1=7+1/2

x1=8/2

x1=4

x2=7-1/2

x2=6/2

x2=3

Espero ter ajudado:)