Question

Determine as raízes das equações do segundo grau. a) x2+6x+5=0 b) x2-7x+6=0 c) 7x-21=0 d)x2-144=0

Answer 1

Explicação passo-a-passo:

x²+6x+5=0

a=1

b=6

c=5

∆=b²-4ac

∆=6²-4*1*5

∆=36-20

∆=16

-b±√∆/2a

-6±√16/2*1

-6±4/2

x¹=-6+4/2=-2/2=>-1

x²=-6-4/2=-10/2=>-5

x²-7x+6=0

a=1

b=-7

c=6

∆=b²-4ac

∆=(-7)²-4*1*6

∆=49-24

∆=25

-b±√∆/2a

7±√25/2*1

7±5/2

x¹=7+5/2=12/2=>6

x²=7-5/2=2/2=>1

7x²-21=0

7x²-21=0(÷7)

x²-3=0

x²=0+3

x²=3

x=±√3

S=>{ √3 e -√3}

x²-144=0

x²=0+144

x²=144

x=±√144

x=±12

S=>{ 12 e -12}