Решение и ответ:

[tex]\displaystyle 2.75\divx=1\frac{2}{3}[/tex]

[tex]\displaystyle x=2.75\div1\frac{2}{3}[/tex]

[tex]\displaystyle x=2\frac{3}{4}\div1\frac{2}{3}[/tex]

[tex]\displaystyle x=\frac{{11}}{4}\div\frac{5}{3}[/tex]

[tex]\displaystyle x=\frac{{11}}{4}\cdot\frac{3}{5}=\frac{{33}}{{20}}[/tex]

[tex]\displaystyle \boxed{x=1\frac{{13}}{{20}}=1.65}[/tex]