206abc : 501=abc
﴾206000 + abc﴿:501 = abc
﴾206000 + abc﴿:abc = 501
206000:abc + 1 = 501
206000 : abc = 500
=> abc = 206000 : 500 = 412
206abc : 501 = abc
=> 206000 + abc = 501 . abc
=> 206000 = 501 . abc - abc
=> 206000 = 500 . abc
=> abc = 206000 : 500
=> abc = 412
Vậy a = 4; b = 1; c = 2.
\(\Leftrightarrow\overline{206abc}=501\times\overline{abc}\)
\(\Leftrightarrow206000+\overline{abc}=501\times\overline{abc}\)
\(\Leftrightarrow206000=500\times\overline{abc}\)
\(\Leftrightarrow\overline{abc}=\frac{206000}{500}=412\)
Vậy, a = 4; b = 1; c = 2.
