Huy Toàn 8A (TL) 05/08/2018 at 13:38
Sum of odd-numbered digits ( - ) Sum of even-numbered digits or vice versa is divisible by 11
(2 + D + D) - (3 + 6 + 9) is divisible by 11
<=> 2 + 2D - 18 is divisible by 11
<=> 2D - 16 is divisible by 11
<=> 2 (D - 8) is divisible by 11
So Greatest common divisor (2 ; 11) = 1
=> D - 8 is divisible by 11
0 \(\le D\le9\)
=> D = 8
So The answer is : 386,892Selected by MathYouLike
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