Ответ: формула -- Al2O3

[tex]\large \boldsymbol {} \bf AlxOy\\\\ W(Al) : W(O) = \displaystyle \frac{52,94}{27} : \frac{47,06}{16} = 1,\!96 : 2,\!94 = 1 : 1,\!5 = 2 : 3 \\\\x = 2; y = 3 ~ \xrightarrow { tu ~~ \xrightarrow {da} ~~} ~ Al_2O_3[/tex]