Question

Me ajudem pfvvvvvvvv

Answer 1

Explicação passo-a-passo:

a) x²+6x +9=0

a= 1

b= 6

c=9

∆= 6² -4.1.9

∆= 36 - 36

∆= 0

x= - 6 ±√0/2.1

x= - 6/2

x= -3

S= { - 3}

b) x²+4x -21=0

a= 1

b=4

c= -21

∆= 4² -4.1.(-21)

∆= 16 + 84

∆= 100

x= - 4 ±√100/2.1

x= -4 ±10/2

x1= -4+10/2

x1= +6/2

x1= 3

x2= -4-10/2

x2= -14/2

x2= -7

S= { 3, -7}