\[ X + A + 72 + B + E + 8 + F = C + 79 + D +10 \]
\[ X + C + 72 + D + 8 = A + 79 + E + B + 10 + F\]
整理一下，
\[ X + 80 + A + B + E + F = C + D +89 \]
\[89 + A + E + B + F =X + C + D + 80 \]
上面两式相减
\[X - 9 = 9 - X 。\]
所以
\[X = 9.\]
鎵�璺熷笘: 脗陆脝脽 : 碌脷露镁脤芒 Area=9 2022-06-06 03:34:22
陆芒路篓2022-06-06 04:28:46 [鐐瑰嚮:1164]
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