Respostas

2014-03-19T21:24:36-03:00
4% de 350 = 0,04 x 350
0,04 x 350 = 14

10% de 1400 = 0,10 x 1400
10 x 1400 = 140

15% de 1400 = 0,15 x 1400
0,15 x 1400 = 230

20% de 3450 = 0,20 x 3450
0,20 x 3450 = 690

:)
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2014-03-19T21:27:05-03:00
Letra a : 

350 ----- 100 %
   x ------    4 %

100x = 350 . 4
100x = 1400
x = 1400 / 100
x = 14

Letra b : 

1,400 -------- 100 %
      x ---------   10 %

100x = 1,400 . 10
100x = 14
x = 14 / 100
x = 0,14

Letra c : 

1,400 ------ 100 %
       x -----   15 %

100x = 1,400 . 15
100x = 21
x = 21 / 100
x = 0,21

Letra d : 

3,450 ------- 100 %
       x ------   20 % 

100x = 3,450 . 20
100x = 69
x = 69 / 100
x = 0,69 
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