GABARITO DA AVALIAÇÃO FINAL DA II UNIDADE

QUADRO DE RESPOSTAS

01	02	03	04	05	06	07	08	09	10	11	12
(a)	(a)	(a)	(a)	(a)	(a)	(a)	(a)	(a)	(a)	(a)	(a)
(b)	(b)	(b)	(b)	(b)	(b)	(b)	(b)	(b)	(b)	(b)	(b)
(c)	(c)	(c)	(c)	(c)	(c)	(c)	(c)	(c)	(c)	(c)	(c)
(d)	(d)	(d)	(d)	(d)	(d)	(d)	(d)	(d)	(d)	(d)	(d)
(e)	(e)	(e)	(e)	(e)	(e)	(e)	(e)	(e)	(e)	(e)	(e)

 

Cálculos das questões 09 a 12.

09.          3x²  - 27 = 0

                3x²  =  27

                x²  =     27    .

                              3

                x²  =  9

                x  =  ± √  9

                x  =  ± 3

          S = { - 3 ,  3 }

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10.            4x² - 1 = 0 

                4x²  =  1                                                      

                  x²  =       1   .

                                 4

               

                  x =  ±    √  1   .

                                √ 4

              

                   x  =      1    .

                               2

São números compreendidos entre – 1 e 1.

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11.     x² = 2x                                                                   

          x²  - 2x  = 0                                                         x  -  2  =  0

         x( x  - 2 ) = 0                                                            x  =  2

             x  =  0

    

    

 É um número par, menor que  7   ou   é um número primo maior que 1,8.

                                                   3

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12.    – x² + 5x = 0     . (-1)                                                3x² – 243 = 0

             x² - 5x = 0                                                              3x² = 243

         x(x – 5) = 0                                                                 x²  =     243  .

             x  =  o                                                                                    3

        x  -  5  =  0                                                                    x²  =  81

        x  =  5                                                                            x  = ± √  81

                                                                                               x  =  ±  9

   Soma das raízes positivas:  5 + 9 = 14

                   

                   

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