abc = a . 100 + b . 10 + c
bca = b .100 + c .10 + a
cab = c . 100 + a . 10 + b
( a . 100 + b .10 + c ) + ( b . 100 + c.10 + a ) + ( c .100 + a . 10 + b )
= a .111 + b . 111 + c .111
= 111 . ( a + b + c )
suy ra abc + bca + cab lớn hơn hoặc bằng 111
Những Con Số
abc = a . 100 + b . 10 + c
bca = b .100 + c .10 + a
cab = c . 100 + a . 10 + b
( a . 100 + b .10 + c ) + ( b . 100 + c.10 + a ) + ( c .100 + a . 10 + b )
= a .111 + b . 111 + c .111
= 111 . ( a + b + c )
suy ra abc + bca + cab lớn hơn hoặc bằng 111
abc = a . 100 + b . 10 + c
bca = a . 100 + c . 10 + a
cab = c . 100 + a . 10 + b
( a . 100 + b . 10 + c ) + ( b .100 + c . 10 + a ) + ( c . 100 + a . 10 + b )
= a . 111 + b . 111 + c . 111
= 111 . ( a + b + c )
\(\Rightarrow\) abc + bca + cab lớn hơn hoặc bằng 111
abc = a . 100 + b . 10 + c
bca = b .100 + c .10 + a
cab = c . 100 + a . 10 + b
( a . 100 + b .10 + c ) + ( b . 100 + c.10 + a ) + ( c .100 + a . 10 + b )
= a .111 + b . 111 + c .111
= 111 . ( a + b + c )
suy ra abc + bca + cab lớn hơn hoặc bằng 111
abc = a . 100 + b . 10 + c
bca = a . 100 + c . 10 + a
cab = c . 100 + a . 10 + b
=>( a . 100 + b . 10 + c ) + ( b .100 + c . 10 + a ) + ( c . 100 + a . 10 + b )
=> a . 111 + b . 111 + c . 111
=> 111 . ( a + b + c )
⇒ abc + bca + cab lớn hơn hoặc bằng 111