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  • Usuário do Brainly
2014-06-10T01:01:05-03:00
A) -3x +12≥ 0

-3x ≥ -12
 3x≤12
x ≤12/3
x ≤4
D= {x ∈ R/ x  ≤  4}

b)  x-3 >0
x > 3

D= {x∈ R /x >3}

4) \frac{-x}{2}   +   \frac{9}{2}    =0




-x =-9
 x=9



9x -81=0
9x=81
x = 81÷9
x =9


6) sen = 5/6

   cosa =√11/6

   tga = 5/√11 = 5√11/11

  sena/cosa= tga = 5√11/11

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