Răspunsuri

2014-09-19T21:08:59+03:00
2/100=md/200 => md=2*200/100= 4 g Na
 5/100=4+x/200+x =>
5(200+x)= 100(4+x)
1000+5x=400x+100x
600=95x
x=6,31 g Na trebuie adaugat
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