+)$P_{x}$ $O_{y}$
QTHT: ax=by
⇔$\frac{x}{y}$ =$\frac{b}{a}$ =$\frac{II}{V}$ =$\frac{2}{5}$
⇔x=2,y=5
$P_{2}$ $O_{5}$
+)$Fe_{x}$ $Cl_{y}$
QTHT: ax=by
⇔$\frac{x}{y}$ =$\frac{b}{a}$ =$\frac{I}{II}$ =$\frac{1}{2}$
⇔x=1,y=2
Fe $Cl_{2}$
+)$Al_{x}$ $(SO_{4}) _{y}$
QTHT: ax=by
⇔$\frac{x}{y}$ =$\frac{b}{a}$ =$\frac{II}{III}$ =$\frac{2}{3}$
⇔x=2,y=3
$Al_{2}$ $(SO_{4})_{3}$
+)$Ca_{x}$ $(PO_{4}) _{y}$
QTHT: ax=by
⇔$\frac{x}{y}$ =$\frac{b}{a}$ =$\frac{II}{III}$ =$\frac{2}{3}$
⇔x=2,y=3
$Ca_{2}$ $(PO_{4})_{3}$
Vote 5* nha <3 :333