Question

A)x²+6x+8=0
B)x²-4x+4=0
C)x²-4x-4=0
D)x²-2x+1=0
E)x²+2x+1=0
F)x²+10x=0
G)x²=81​

Answer 1

a){2 e -4}

b){2}

c){2}

d){1}

e){-1}

f){-5}

g){40,5}

a)x²+6x+8=0

a)1

b)6

c)8

Δ=b² -4.a.c

Δ=6² -4.1.8

Δ=36-32

Δ=4

X= -6±√4/2=

X₁= -6+2/2= 2

X₂= -6-2/2= -4

b)x²-4x+4=0

a)1

b)-4

c)4

Δ=b² -4.a.c

Δ=(-4)² -4.1.4

Δ=16-16

Δ=0

X= 4±√0/2=

X₁= 4/2= 2

c) x²-4x-4=0

a)1

b)-4

c)-4

Δ=b² -4.a.c

Δ=(-4)² -4.1.(-4)

Δ=16+16

Δ=32

X= 4±√32/2=

X₁= 4/2= 2

d)x²-2x+1=0

a)1

b)-2

c)1

Δ=b² -4.a.c

Δ=(-2)² -4.1.1

Δ=4-4

Δ=0

X= 2±√0/2=

X₁= 2/2= 1

e)x²+2x+1=0

a)1

b)2

c)1

Δ=b² -4.a.c

Δ=2² -4.1.1

Δ=4-4

Δ=0

X= -2±√0/2=

X₁= -2/2=-1

f)x²+10x=0

a)1

b)10

c)0

Δ=b² -4.a.c

Δ=10² -4.1.0

Δ=100-4

Δ=96

X= -10±√96/2=

X₁= -10/2=-5

g)x²=81

x²-81=0

a)1

b)-81

c)0

Δ=b² -4.a.c

Δ=(-81)² -4.1.0

Δ=6561-4

Δ=6557

X= 81±√6557/2=

X₁= 81/2= 40,5