Dế thấy \(0,\overline{xy}< 1\Rightarrow19.94+0,\overline{xy}< 20,94\)
\(\Rightarrow\overline{xy},\overline{mn}< 20,94\Rightarrow\overline{xy}\le20\)
Mà\(19,94< \overline{xy},\overline{mn}\Rightarrow\overline{xy}\ge19\)
\(\Rightarrow\overline{xy}=19;\overline{xy}=20\)
Nếu \(\overline{xy}=19\Rightarrow19,\overline{mn}=19,94+0,19=20,13\left(L\right)\)
Nếu \(\overline{xy}=20\Rightarrow20,\overline{mn}=19,94+0,20=20,14\Rightarrow\overline{mn}=14\)
Vậy ta có phép tính sau: 20,14=19,94+0,20