Question

RESOLVA AS PROPORÇÕES

a) 2x+1 / 10 = -21 / 30
b)3x + 2 / x + 3 = -40 / 25
c) 0,3/x = -6/9
d) 7x + 5 /4 = 2x/3/4

Answer 1

a) 2x+1 = -21 =>60x + 30= - 210 => 60x = - 210-30=>60x= - 240 ==>x = -40
       10      30
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b)3x + 2 = -40 
    x + 3       25  

75x +50= -40x -120 => 75x+40x= -120-50=> 115x=-175 ==> x= - 175/115
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c) 0,3/x = -6 ==> -6x = 2,7(-1) ==> 6x=27 => 60x= 27==> x = 27/60  
      x         9                                           10
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d) 7x + 5 = 2x : 4 ==> 7x+5 = 2x . 1  ==> 7x+5 = 2x
        4         3    1             4      3    4             4      12

84x + 60 = 8x ==> 84x - 8x = - 60 ==> 76x = - 60 ==> x = - 60/76