Respostas

  • Usuário do Brainly
2014-06-10T17:38:35-03:00
3x² - 9x = 0
x . (3x - 9) = 0
x = 0
3x - 9 = 0
3x = 9
x = 9/3
x = 3
2014-06-10T17:53:24-03:00
3x²-9x=0
▲=81-4.3.0
▲=81-0
▲=81
x=9+-√81
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    2.(a)

x=9+-9
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    2.3

x=9+-9    /→ 18/6=3
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    6         \→ 0/6=0