Respostas

2014-04-11T13:17:59-03:00
40---100%
 x----30%

100x=1200
x= \frac{1200}{100} =R$12,00
1 5 1
2014-04-11T13:27:55-03:00
30% x 40 =1200/100= 12 reais
1 5 1