Question

Resolva, Em R, as equaçoes.​

Answer 1

a)x²+5x+6=0

∆=5²-4.(1).(6)

∆=25-24

∆=1

x=-5±√1/2.1

x=-5±1/2

x'=-4/2=-2

x"-6/2=-3

S={-3,-2}

b)x²-8x+7=0

∆=(-8)²-4.(1).(7)

∆=64-28

∆=36

x=8±√36/2.1

x=8±6/2

x'=14/2=7

x"=2/2=1

S={1,7}

c)x²-6x+8=0

∆=(-6)²-4.(1).(8)

∆=36-32

∆=4

x=6±√4/2.1

x=6±2/2

x'=8/2=4

x"=4/2=2

S={2,4}

d)x²-x-20=0

∆=(-1)²-4.(1).(-20)

∆=1+80

∆=81

x=1±√81/2.1

x=1±9/2

x'=10/2=5

x"=-8/2=-4

S={-4,5}

e)2x²-5x+3=0

∆=(-5)²-4.(2).(3)

∆=25-24

∆=1

x=5±√1/2.2

x=5±1/4

x'=6/4= 3/2

x"=4/4=1

S={1,3/2}

f)6x²-x-2=0

∆=(-1)²-4.(6).(-2)

∆=1+48

∆=49

x=1±√49/2.6

x=1±7/12

x'=8/12= 2/3

x"=-6/12= -1/6

S={-1/6, 2/3}