Question

rozwiąż równania

a)

b)

c)

d)

Answer 1

a)

3 x^2 = - 2x

3 x^2 + 2x = 0

x*(3x + 2) = 0

x = 0   v   3x + 2 = 0

x = 0  v  3x = - 2

x = 0  v  x = - 2/3

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b)

4 x^2 - 81 = 0

(2x)^2 - 9^2 = 0

(2x - 9)*(2x + 9) = 0

2x = 9  v  2x = - 9

x = 4,5  v  x = - 4,5

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c)

5 +  5 x^2 = 8 x

5 x^2 - 8 x + 5 = 0

delta = (-8)^2 - 4*5*5 = 64 - 100 < 0

Brak rozwiązań.

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d)

16 - ( 3x - 1)^2 = 0

16 - ( 9 x^2 - 6 x + 1 ) = 0

16 - 9 x^2 + 6 x - 1 = 0

9 x^2 - 6x - 15 = 0  / : 3

3 x^2 - 2 x - 5 = 0

delta = (-2)^2 - 4*3*(-5) = 4 + 60 = 64

p (delty) = 8

x = [  2 - 8]/6 = -6/6 = - 1

v

x =[ 2 + 8]/6 = 10/6 = 5/3

x = - 1     v    x =  5/3

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