Question

Equação do segundo grau

a) x^2-10x=0

b) x^2+11x=0

c) 3x^2-12x=0

d)5x^2+25x=0

e) -2x^2+8x=0

f) -4x^2+16x=0

(^ = sobre)

preciso da conta.

Answer 1

a)
x² - 10x = 0
x.(x - 10) = 0
x = 0
x - 10 = 0
x = 10

R.: x = 0; x = 10


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b)
x² + 11x = 0
x.(x + 11) = 0
x = 0
x + 11 = 0
x = - 11

R.: x = 0  ;x = - 11

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c)
3x² - 12x = 0
x.(3x - 12) = 0
x = 0

3x - 12 = 0
3x = 12
x = 12/3
x = 4

R.: x = 0 / x = 4

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d)
5x² + 25x = 0
x.(5x + 25) = 0
x = 0
5x + 25 = 0
5x = - 25
x = -25/5
x = - 5

R.: x = 0 ; x = - 5

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e)
- 2x² + 8x = 0
x.(-2x + 8) = 0
x = 0
- 2x + 8 = 0 
- 2x = - 8 (-1)
2x = 8
x = 8/2
x = 4

R.: x = 0 ; x = 4

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f)
-4x² +16x = 0
x.(-4x + 16) = 0
x = 0
- 4x + 16 = 0
- 4x = - 16 (-1)
4x = 16
x = 16/4
x = 4

R.: x = 0 ; x = 4