resolva as equações do 2° grau em IR:
A)ײ-5×+6=0
B)ײ-8×+12=0
C)ײ+2×-8=0
D)ײ-5×+8=0
E)2ײ-8×+8=0
F)ײ-4×-5=0
G)-ײ+×+12=0
H)-ײ+ 6×-5=0
Soluções para a tarefa
Resposta:Segue as contas abaixo na explicação
Explicação passo-a-passo:
A)ײ-5×+6=0 B)ײ-8×+12=0 C)ײ+2×-8=0
Δ=b²-4.a.c Δ=b²-4.a.c Δ=b²-4.a.c
Δ=(-5)²-4.1.6 Δ=(-8)²-4.1.12 Δ=2²-4.1.(-8)
Δ=25-24 Δ=64-48 Δ=4+32
Δ=1 Δ=16 Δ=36
x=-b ± √Δ/2.a x=-b ± √Δ/2.a x=-b ± √Δ/2.a
x=-(-5) ± √1/2.1 x=-(-8) ± √16/2.1 x=-4 ± √36/2.1
x=5 ± 1/2 x=8 ± 4/2 x=4 ±6/2
x1=5+1/2 x1=8+4/2 x1=4+6/2
x1=6/2 x1=12/2 x1=10/2
x1=3 x1=6 x1=5
x2=5-1/2 x2=8-4/2 x2=4-6/2
x2=4/2 x2=4/2 x2=-2/2
x2=2 x2=2 x2=-1
S(3,2) S(6,2) S(5,-1)
D)ײ-5×+8=0 E)2ײ-8×+8=0 F)ײ-4×-5=0
Δ=b²-4.a.c Δ=b²-4.a.c Δ=b²-4.a.c
Δ=(-5)²-4.1.8 Δ=(-8)²-4.2.8 Δ=(-4)²-4.1.(-5)
Δ=25-32 Δ=64-64 Δ=16+20
Δ=-7(não ha solução) Δ=0 Δ=36
x=-b ± √Δ/2.a x=-b ± √Δ/2.a
x=-(-8) ± √0/2.2 x=-(-4) ± √36/2.1
x=8 ± 0/4 x=4 ±6/2
x1=8+0/4 x1=4+6/2
x1=8/4 x1=10/2
x1=2 x1=5
x2=8-0/4 x2=4-6/2
x2=8/4 x2=-2/2
x2=2 x2=-1
S(2,2) S(5,-1)
G)-ײ+×+12=0 H)-ײ+ 6×-5=0
Δ=b²-4.a.c Δ=b²-4.a.c
Δ=1²-4.(-1).12 Δ=6²-4.(-1).(-5)
Δ=1+48 Δ=36-20
Δ=49 Δ=16
x=-b ± √Δ/2.a x=-b ± √Δ/2.a
x=-1 ± √49/2.(-1) x=-6 ± √16/2.(-1)
x=-1 ± 7/-2 x=-6 ± 4/-2
x1=-1+7/-2 x1=-6+4/-2
x1=6/-2 x1=-2/-2
x1=-3 x1=1
x2=-1-7/-2 x2=-6-4/-2
x2=-8/-2 x2=-10/-2
x2=4 x2=5
S(-3,4) S(1,5)