Question

Determine as raizes das equações a seguir:
X²+6×-7=0

X²+3×-10=0

X²+2×+1=0

X²+2×-3=0

Answer 1

Explicação passo-a-passo:

X²+6x-7=0

a=1

b=6

c=-7

∆=b²-4.a.c

∆=(6)²-4.(1).(-7)

∆=36+28

∆=64

x'=[-(+6)+√64]/2.(1)

x'=[-6+8]/2

x'=2/2

x'=1

x"=[-(+6)-√64]/2.(1)

x"=[-6 -8]/2

x"=-14/2

x"=-7

S={( -7 : 1)}

X²+3x-10=0

a=1

b=3

c=-10

∆=b²-4.a.c

∆=(3)²-4.(1).(-10)

∆=9+40

∆=49

x'=[-(+3)+√49]/2.(1)

x'=[-3+7]/2

x'=4/2

x'=2

x"=[-(+3)-√49]/2.(1)

x"=[-3-7]/2

x"=-10/2

x"=-5

S={( -5 : 2)}

X²+2x+1=0

a=1

b=2

c=1

∆=b²-4.a.c

∆=(2)²-4.(1).(1)

∆=4-4

∆=0

x'=x"=-b/2a=-(+2)/2.(1)=-2/2=-1

S={(-1)}

X²+2x-3=0

a=1

b=2

c=-3

∆=b²-4.a.c

∆=(2)²-4.(1).(-3)

∆=4+12

∆=16

x'=[-(+2)+√16]/2.(1)

x'=[-2+4]/2

x'=[2]/2

x'=1

x"=[-(+2)-√16]/2.(1)

x"=[-2-4]/2

x"=-6/2

x"=-3

S={( -3 : 1)}