m.apa = 500 g
c% sol = 30%
stim ca c% = mdx100/ms
si mai stim ca ms = md + 500
=> 30 = mdx100/(md+500)
=> 30(md+500) = 100md
=> md = 15000/70 = 214,3 g
facem proba:
ms = 714,3 g
md = 214,3
=> c = 214,3x100/714,3 = 30% deci verifica
scuze de confuzie.......