1)
[tex] \frac{c}{100} = \frac{md}{ms} [/tex]
[tex] \frac{c}{100} = \frac{20}{20 + 180} \\ \frac{c}{100} = \frac{20}{200} [/tex]
[tex] \frac{c}{100} = \frac{2}{20} \\ c = \frac{100 \times 2}{20} \\ c = \frac{10 \times 2}{2} [/tex]
C=10 %
2)
[tex] \frac{10}{100} = \frac{md}{300} [/tex]
[tex]md = \frac{10 \times 300}{100} [/tex]
[tex]md = \frac{10 \times 3}{1} [/tex]
[tex]md = 30g[/tex]
ms=md+m H2O (H2O este apa)
300=30+m H20
m H20=300-30
m H20=270g
Sper că te-am ajutat si baftă in continuare! :D
