POR FAVOR ME AJUDEM URGENTE!

1) Resolva as equações do 2° grau em R . Aplique a fórmula de
Bhaskara. (registre cálculos)
a) (x)^(2) -7x+ 6=0
b) (x)^(2) - 8x+ 15=0
c) (x)^(2)+10x+25=0
d) (3x)^(2)+4x+1=0
e) (x)^(2)-12x+20=0
f) (x)^(2)+ 5x+6=0
g) (x)^(2)- 7x+ 12=0
h) (x)^(2)+5x+4=0
i) (2x)^(2)+3x+1=0
j) (x)^(2)-18x+45=0

Obrigada!

1

Respostas

2013-06-22T19:46:37-03:00

Δ=b²-4.a.c

x=-b±√Δ /2.a(dividido por 2.a)

 

a) (x)^(2) -7x+ 6=0

Δ=(-7)²-4.1.6

Δ=49-24

Δ=25

x=-(-7)±√25/2.1

x=7±5/2

x'=7+5/2⇒x'=12/2⇒x'=6

x"=7-5/2⇒x"2/2⇒x"=2

 

b) (x)^(2) - 8x+ 15=0

Δ=(-8)²-4.1.15

Δ=64-60

Δ=4

x=-(-8)±√4/2.1

x=8±2/2

x'=8+2/2⇒x'=10/2⇒x'=5

x"8-2/2⇒x"=6/2⇒x"=3

 

c) (x)^(2)+10x+25=0

Δ=10²-4.1.25

Δ=100-100

Δ=0

x=-10±√0/2

x'=-10/2⇒x'=-5

x"=-10/2⇒x"=-5

 

d) (3x)^(2)+4x+1=0

Δ=4²-4.3.1

Δ=16-12

Δ=4

x=-4±√4/2.3

x=-4±2/6

x'=-4+2/6⇒x'=-2/6⇒x'=-1/3

x"=-4-2/6⇒x"=-6/6⇒x"=-1

 

f) (x)^(2)+ 5x+6=0

Δ=5²-4.1.6

Δ=25-24

Δ=1

x=-5±√1/2.1

x=-5±1/2

x'=-5+1/2⇒x'=-4/2⇒x'=-2

x"=-5-1/2⇒x"=-6/2⇒x"=-3

 

g) (x)^(2)- 7x+ 12=0

Δ=(-7)²-4.1.12

Δ=49-48

Δ=1

x=-(-7)±√1/2.1

x=7±1/2

x'=7+1/2⇒x'=8/2⇒x'=4

x"=7-1/2⇒x"=6/2⇒x"=3

 

h) (x)^(2)+5x+4=0

Δ=5²-4.1.4

Δ=25-16

Δ=9

x=-5±√9/2.1

x=-5±3/2

x'=-5+3÷2⇒x'=-2/2⇒x'=-1

x"=-5-3÷2⇒x"=-8/2⇒x"=-4

 

i) (2x)^(2)+3x+1=0

Δ=3²-4.2.1

Δ=9-8

Δ=1

x=-3±√1/2.1

x=-3±1/2

x'=-3+1/2⇒x'=-2/2⇒x'=-1

x"=-3-1/2⇒x"=-4/2⇒x"=-2

 

j) (x)^(2)-18x+45=0

Δ=(-18)²-4.1.45

Δ=324-180

Δ=144

x=-(-18)±√144/2.1

x=18±12/2

x'=18+12/2⇒x'=30/2⇒x'=15

x"=18-12/2⇒x"6/2⇒x"=3

 

OBS.: Não consegui fazer o exercício E, desculpa!

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