Question

RESOLVA AS EQUAÇÕES DO 2º GRAU

1) x² - 5x + 6 = 0
2) x² - 8x + 12 = 0
3) 2x² - 8x + 8 = 0
4) x² - 4x - 5 = 0

Answer 1

1) x² - 5x + 6 = 0

delta = (-5)² - 4.1.6
delta = 25 - 24
delta = 1

x = -(-5) ± √1/2.1

x = 5 ± 1/2

x = 5 - 1/2 = 4/2 = 2

x = 5 +1/2 = 6/2 = 3

s={ 2, 3}




2) x² - 8x + 12 = 0


delta = (-8)² - 4.1.12
delta = 64 - 48
delta = 16


x = -(-8) ± √16/2.1


x = 8 ± 4/2

x = 8 - 4/2 = 4/2 = 2

x = 8 + 4/2 = 12/2 = 6

s={ 2, 6}


3) 2x² - 8x + 8 = 0

delta = (-8)² - 4.2.8
delta = 64 - 64
delta = 0

x = -(-8) ± √0/2.2

x = 8 ± 0/4 = 8/4 = 2

s={ 2 }



4) x² - 4x - 5 = 0


delta = (-4)² - 4.1.(-5)
delta = 16 + 20
delta = 36


x = -(-4) ± √36/2.1

x = 4 ± 6/2

x = 4 - 6/2 = -2/2 = -1

x = 4 + 6/2 = 10/2 = 5

s={ -1, 5}



Ufa, Espero ter ajudado!

Answer 2

1) x²-5x+6=0
a=1 b=-5 c=6
∆=-b²-4.a.c
∆=-(-5)²-4.1.6
∆=25-24
∆= 1

x=-b²±√∆/2.a
x=-(-5)±√1/2.1
x=5±1/2
x'=5+1/2 = 6/2 = 3
x''=5-1/2 = 4/2 =2
s={(3,2)}


2) x²-8x+12=0
a=1 b=-8 c=12
∆=-b²-4.a.c
∆=-(-8)²-4.1.12
∆=64-48
∆=16

x=-b±√∆/2.a
x=-(-8)±√16/2.1
x=8±4/2
x'=8+4/2 = 12/2 = 6
x''=8-4/2 = 4/2 = 2
s={(6,2)}


3)2x²-8x+8=0
a=2 b=-8 c=8
∆=-b²-4.a.c
∆=-(-8)²-4.2.8
∆=64-64
∆=0

x=-b±√∆/2.2
x=-(-8)±√0/4
x=8±0/4
x'=8+0/4 = 8/4 = 2
x''=8-0/4 = 8/4 = 2
s={(2,2)}


4)x²-4x-5=0
a=1 b=-4 c=-5
∆=-b²-4.a.c
∆=-(-4)²-4.1.(-5)
∆=16+20
∆=36

x=-b±√∆/2.1
x=-(-4)±√36/2
x=4±6/2
x'=4+6/2 = 10/2 = 5
x''=4-6/2 = -2/2 = -1
s={(5,-1)}