Question

URGENTE!!) RESOLVA AS EQUAÇÕES DO 2° GRAU.

a) 8x^2 = 0

b) x^2 - 7 = 0

c) 3x^2 + 21x = 0

d) -2x^2 + x = 0

e) -5x^2 + 7x = 0

f) 6x^2 - 10x = 0

Answer 1

a) 8x² =0

Δ=0²-4.8.0

Δ=0

x= 0±0/2.8

x=0/16=0

b)  x² - 7 = 0

Δ= 0²-4.1.(-7)

Δ= 28

c) 3x²+21x = 0

Δ= 21²-4.3.0

Δ=441

x= -21±√441 /2.3

x= -21±21/6

x,=0/6=0

x,,= -42/6 = -7

d) -2x² + x = 0

Δ= 1²-4.(-2).0

Δ= 1

x´= -1±√1 /2.(-2)

x= -1±1 /-4

x,=0/-4= 0

x,,= -1-1/-4 = -2/-4 =-1/-2

e) -5x² + 7x = 0

Δ= 7²-4.(-5).0

Δ= 49

x= -7±√49/2.(-5)

x=-7±7 /-10

x=0/-10=0

x,,= -7-7 / -10 = -14/-10 = -7/-5

f) 6x² - 10x = 0

Δ=(-10)²-4.6.0

Δ=100

x= -(-10)±√100 /2.6

x=10±10 /12

x= 10+10/12= 20/12 = 5/3

x,,= 10-10/12 = 0/12=0