Question

2) Determine as raízes reais das equações incompletas do 2 grau a seguir:

a) 2x²-18=0

b)x²-x=0

Answer 1

Resposta:

$a)\\ 2x^2-18=0\\ \\ 2x^2=18\\ \\ x^2=18\div2\\ \\ x^2=9\\ \\ x=\pm\sqrt{9} \\ \\ x=\pm3$

As raízes são -3 e +3

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b)

$x^2-x=0\\ \\ x(x-1)=0\\ \\ x-1=0~~~~~~~~~~~~~x=0\\ x=1$

As raízes sã 0 e 1

Answer 2

a) 2x^2 - 18 = 0

2x^2 = 0 + 18

2x ^2 = 18

x^2 = 18/2

x^2 = 9

x = √9

x = ± 3

x' = 3 e x" = -3

b) x^2 - x = 0

x . (x - 1) = 0

x = 0

x - 1 = 0

x = 0 + 1

x = 1

x' = 0 e x" = 1