Trong b\u00e0n c\u1edd t\u01b0\u1edbng Trung Qu\u1ed1c con \u201cm\u00e3\u201d \u0111i theo quy t\u1eafc l\u00e0 nh\u1ea3y \u0111\u1ebfn \u0111\u1ec9nh \u0111\u1ed1i di\u1ec7n c\u1ee7a ch\u1eef nh\u1eadt. Li\u1ec7u con \u201cm\u00e3\u201d c\u00f3 th\u1ec3 \u0111i \u0111\u1ebfn v\u1ecb tr\u00ed b\u1ea5t k\u00ec tr\u00ean b\u00e0n c\u1edd kh\u00f4ng? C\u00e2u k\u1ebft lu\u1eadn l\u00e0 \u201cc\u00f3\u201d, c\u00f3 th\u1ec3 ch\u1ee9ng minh kh\u00e1 \u0111\u01a1n gi\u1ea3n.<\/p>\n\n\n\n
Hi\u1ec3n nhi\u00ean ch\u1ec9 c\u1ea7n con \u201cm\u00e3\u201d \u0111i \u0111\u1ebfn \u0111\u01b0\u1ee3c hai v\u1ecb tr\u00ed \u1edf c\u1ea1nh nhau tr\u00ean b\u00e0n c\u1edd. Nh\u01b0 tr\u00ean h\u00ecnh 1 gi\u1ea3 \u0111\u1ecbnh v\u1ecb tr\u00ed ban \u0111\u1ea7u c\u1ee7a con \u201cm\u00e3\u201d t\u1ea1i \u0111i\u1ec3m A, ta c\u1ea7n \u0111\u01b0a con m\u00e3 \u0111\u1ebfn v\u1ecb tr\u00ed B c\u1ea1nh \u0111\u00f3. Ch\u00fang ta c\u00f3 th\u1ec3 th\u1ea5y A ho\u1eb7c B \u1edf tr\u00ean khu v\u1ef1c m\u1ed9t ch\u1eef \u0111i\u1ec1n \u2f65 tr\u00ean b\u00e0n c\u1edd. Ta c\u00f3 th\u1ec3 ch\u1ee9ng minh con \u201cm\u00e3\u201d c\u00f3 th\u1ec3 d\u1ef1a theo quy t\u1eafc \u0111i nh\u1ea3y trong ph\u1ea1m vi ch\u1eef \u0111i\u1ec1n \u0111\u00e3 ch\u1ecdn l\u00e0 c\u00f3 th\u1ec3 \u0111\u1ebfn \u0111\u01b0\u1ee3c \u0111i\u1ec3m B \u1edf l\u00e2n c\u1eadn A. C\u00e1c khu v\u1ef1c c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c ch\u1ecdn l\u00e0 m\u1ed9t trong hai khu v\u1ef1c \u0111\u1ed1i x\u1ee9ng nh\u01b0 \u1edf h\u00ecnh 1 v\u00e0 h\u00ecnh 2. Con m\u00e3 t\u1eeb A \u0111i \u0111\u1ebfn B \u1edf h\u00ecnh 1 ho\u00e0n to\u00e0n gi\u1ed1ng nh\u01b0 \u1edf h\u00ecnh 2, v\u00ec v\u1eady ta ch\u1ec9 c\u1ea7n x\u00e9t tr\u01b0\u1eddng h\u1ee3p nh\u01b0 h\u00ecnh 1.<\/p>\n\n\n\n
Ta c\u00f3 th\u1ec3 d\u00f9ng h\u1ec7 to\u1ea1 \u0111\u1ed9 vu\u00f4ng g\u00f3c. Gi\u1ea3 s\u1eed to\u1ea1 \u0111\u1ed9 c\u1ee7a A \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n A (0,0) \u0111i \u0111\u1ebfn \u0111i\u1ec3m B (0,1) ta c\u00f3 th\u1ec3 d\u00f9ng ba n\u01b0\u1edbc \u0111i A (0,0) \u2192 (1,2) \u2192(2,0) \u2192 B (0,1).<\/p>\n\n\n\n
\u0110i\u1ec1u \u0111\u00f3 ch\u1ee9ng minh k\u1ebft lu\u1eadn \u0111\u00e3 n\u00eau tr\u00ean.<\/p>\n\n\n\n
Nh\u01b0 v\u1eady v\u1ea5n \u0111\u1ec1 \u0111\u1eb7t ra \u0111\u00e3 \u0111\u01b0\u1ee3c tr\u1ea3 l\u1eddi. Nh\u01b0 v\u1eady t\u1eeb ph\u01b0\u01a1ng ph\u00e1p \u0111\u01a1n gi\u1ea3n l\u00e0 d\u00f9ng h\u1ec7 to\u1ea1 \u0111\u1ed9 vu\u00f4ng g\u00f3c \u0111\u1ec3 gi\u1ea3i quy\u1ebft b\u00e0i to\u00e1n, ta c\u00f3 th\u1ec3 bi\u1ebfn v\u1ea5n \u0111\u1ec1 cho d\u00f9 nh\u00ecn qua kh\u00e1 ph\u1ee9c t\u1ea1p th\u00e0nh v\u1ea5n \u0111\u1ec1 c\u00f3 th\u1ec3 gi\u1ea3i quy\u1ebft \u0111\u01b0\u1ee3c b\u1eb1ng bi\u1ec7n ph\u00e1p \u0111\u01a1n gi\u1ea3n.<\/p>\n\n\n\n
C\u1ea7n bao nhi\u00eau ph\u00e9p th\u1eed \u0111\u1ec3 t\u00ecm \u0111\u01b0\u1ee3c m\u1ed9t ph\u1ebf ph\u1ea9m trong 81 s\u1ea3n ph\u1ea9m s\u1ea3n xu\u1ea5t ra?<\/p>\n\n\n\n
C\u00f3 81s\u1ea3n ph\u1ea9m \u0111\u01b0\u1ee3c s\u1ea3n xu\u1ea5t ra nh\u01b0ng trong \u0111\u00f3 c\u00f3 m\u1ed9t s\u1ea3n ph\u1ea9m c\u00f3 v\u1ebft r\u1ed7ng b\u1eb1ng h\u1ea1t c\u00e1t n\u00ean tr\u1edf th\u00e0nh ph\u1ebf ph\u1ea9m, c\u1ea7n ph\u1ea3i t\u00ecm ra ph\u1ebf ph\u1ea9m \u0111\u00f3. \u0110\u01b0\u01a1ng nhi\u00ean l\u00e0 nh\u00ecn b\u1eb1ng m\u1eaft th\u01b0\u1eddng ng\u01b0\u1eddi ta kh\u00f4ng th\u1ec3 nh\u1eadn ra ph\u1ebf ph\u1ea9m \u0111\u00f3, do v\u1ebft r\u1ed7ng \u1edf b\u00ean trong ph\u1ebf ph\u1ea9m, n\u00ean ph\u1ebf ph\u1ea9m s\u1ebd nh\u1eb9 h\u01a1n ch\u00ednh ph\u1ea9m. Nh\u01b0 v\u1eady ta c\u00f3 th\u1ec3 d\u00f9ng c\u00e1ch c\u00e2n \u0111\u1ec3 t\u00ecm ra ph\u1ebf ph\u1ea9m. Nh\u01b0ng v\u1ea5n \u0111\u1ec1 \u0111\u1eb7t ra l\u00e0 ph\u1ea3i th\u1ef1c hi\u1ec7n bao nhi\u00eau ph\u00e9p c\u00e2n th\u00ec m\u1edbi t\u00ecm \u0111\u01b0\u1ee3c ph\u1ebf ph\u1ea9m.<\/p>\n\n\n\n
Ph\u01b0\u01a1ng ph\u00e1p ki\u1ec3m tra chung l\u00e0 b\u1ecf hai s\u1ea3n ph\u1ea9m v\u00e0o hai \u0111\u0129a c\u00e2n, n\u1ebfu c\u00e2n kh\u00f4ng b\u1ecb l\u1ec7ch th\u00ec \u0111\u00f3 l\u00e0 hai ch\u00ednh ph\u1ea9m, n\u1ebfu kh\u00f4ng th\u00ec v\u1eadt nh\u1eb9 h\u01a1n s\u1ebd l\u00e0 ph\u1ebf ph\u1ea9m. Nh\u01b0 v\u1eady v\u1edbi l\u1ea7n c\u00e2n \u0111\u1ea7u ti\u00ean ta c\u00f3 th\u1ec3 ph\u00e1t hi\u1ec7n \u0111\u01b0\u1ee3c l\u00e0 c\u00f3 ph\u1ebf ph\u1ea9m hay kh\u00f4ng? N\u1ebfu nh\u01b0 c\u00f3 ba s\u1ea3n ph\u1ea9m ta c\u00f3 th\u1ec3 ph\u00e1t hi\u1ec7n ra ph\u1ebf ph\u1ea9m v\u1edbi m\u1ed9t l\u1ea7n c\u00e2n. B\u1edfi v\u00ec n\u1ebfu ch\u1ec9 c\u00f3 ba v\u1eadt ph\u1ea9m m\u00e0 n\u1ebfu c\u00f3 m\u1ed9t ph\u1ebf ph\u1ea9m th\u00ec khi \u0111\u1eb7t hai v\u1eadt ph\u1ea9m l\u00ean c\u00e2n n\u1ebfu c\u00e2n th\u0103ng b\u1eb1ng th\u00ec ph\u1ebf ph\u1ea9m l\u00e0 v\u1eadt ch\u01b0a \u0111\u01b0a l\u00ean c\u00e2n, c\u00f2n n\u1ebfu c\u00e2n b\u1ecb l\u1ec7ch th\u00ec ph\u1ebf ph\u1ea9m l\u00e0 v\u1eadt nh\u1eb9 h\u01a1n.<\/p>\n\n\n\n
Th\u1ebf n\u1ebfu c\u00f3 ch\u00edn v\u1eadt ph\u1ea9m li\u1ec7u c\u00f3 ph\u1ea3i c\u00e2n \u0111\u1ebfn ch\u00edn l\u1ea7n kh\u00f4ng?<\/p>\n\n\n\n
Tr\u01b0\u1edbc h\u1ebft ta chia s\u1ea3n ph\u1ea9m th\u00e0nh ba \u0111\u1ed1ng, m\u1ed7i \u0111\u1ed1ng c\u00f3 ba s\u1ea3n ph\u1ea9m. Tu\u1ef3 \u00fd ch\u1ecdn hai trong ba \u0111\u1ed1ng \u0111\u1eb7t l\u00ean hai \u0111\u0129a c\u00e2n. V\u1edbi m\u1ed9t l\u1ea7n c\u00e2n b\u1ea1n c\u00f3 th\u1ec3 ph\u00e1t hi\u1ec7n ph\u1ebf ph\u1ea9m \u1edf \u0111\u1ed1ng n\u00e0o. Sau \u0111\u00f3 l\u1ea1i ch\u1ecdn ph\u1ebf ph\u1ea9m t\u1eeb \u0111\u1ed1ng c\u00f3 ch\u1ee9a ph\u1ebf ph\u1ea9m. Sau \u0111\u00f3 d\u00f9ng bi\u1ec7n ph\u00e1p nh\u01b0 tr\u00ean ta c\u00f3 th\u1ec3 t\u00ecm \u0111\u01b0\u1ee3c ph\u1ebf ph\u1ea9m, nh\u01b0 v\u1eady ch\u1ec9 c\u1ea7n hai l\u1ea7n c\u00e2n.<\/p>\n\n\n\n
D\u1ef1a theo l\u00ed lu\u1eadn t\u01b0\u01a1ng t\u1ef1, ta chia 81 s\u1ea3n ph\u1ea9m th\u00e0nh ba \u0111\u1ed1ng, m\u1ed7i \u0111\u1ed1ng 27 s\u1ea3n ph\u1ea9m. Sau \u0111\u00f3 ch\u1ecdn hai \u0111\u1ed1ng b\u1ea5t k\u00ec trong ba \u0111\u1ed1ng, \u0111\u1eb7t l\u00ean hai \u0111\u0129a c\u00e2n, nh\u1edd \u0111\u00f3 c\u00f3 th\u1ec3 x\u00e1c \u0111\u1ecbnh ph\u1ebf ph\u1ea9m chia l\u00e0m ba nh\u00f3m m\u1ed7i nh\u00f3m ch\u00edn c\u00e1i, l\u1ea1i l\u1ea5y hai trong ba nh\u00f3m \u0111em c\u00e2n. \u0110\u1ebfn \u0111\u00e2y ta \u0111\u00e3 th\u1ef1c hi\u1ec7n b\u1ed1n l\u1ea7n c\u00e2n, nh\u1edd \u0111\u00f3 c\u00f3 th\u1ec3 t\u00ecm \u0111\u01b0\u1ee3c ph\u1ebf ph\u1ea9m trong 81 s\u1ea3n ph\u1ea9m.<\/p>\n\n\n\n
N\u1ebfu nh\u01b0 s\u1ed1 s\u1ea3n ph\u1ea9m nhi\u1ec1u h\u01a1n v\u00ed nh\u01b0 243, 729\u2026ta c\u1ea7n t\u00ecm quy lu\u1eadt. N\u1ebfu nh\u01b0 b\u1ea1n \u0111\u00e3 t\u00ecm ra th\u00ec n\u1ebfu s\u1ed1 linh ki\u1ec7n l\u00e0 3n, th\u00ec n s\u1ebd l\u00e0 s\u1ed1 l\u1ea7n c\u00e2n \u0111\u1ec3 t\u00ecm ph\u1ebf ph\u1ea9m. V\u00ed d\u1ee5 81 = 3n th\u00ec n\u1ebfu c\u1ea7n t\u00ecm ph\u1ebf ph\u1ea9m trong 81 s\u1ea3n ph\u1ea9m ta c\u1ea7n b\u1ed1n l\u1ea7n c\u00e2n. C\u00f2n 243 = 35, 729 = 36 th\u00ec n\u1ebfu c\u1ea7n t\u00ecm ph\u1ebf ph\u1ea9m trong 243, 729 s\u1ea3n ph\u1ea9m th\u00ec s\u1ed1 l\u1ea7n c\u00e2n \u00edt nh\u1ea5t l\u00e0 n\u0103m l\u1ea7n v\u00e0 s\u00e1u l\u1ea7n. N\u1ebfu s\u1ed1 linh ki\u1ec7n kh\u00f4ng b\u1eb1ng 3n th\u00ec ph\u1ea3i l\u00e0m th\u1ebf n\u00e0o? Xin c\u00e1c b\u1ea1n t\u1ef1 t\u00ecm gi\u1ea3i ph\u00e1p.<\/p>\n\n\n\n
L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 s\u1eafp x\u1ebfp kh\u00e9o l\u00e9o 250 qu\u1ea3 t\u00e1o v\u00e0o t\u00e1m chi\u1ebfc gi\u1ecf?<\/p>\n\n\n\n
V\u1ea5n \u0111\u1ec1 nh\u01b0 sau: gi\u1ea3 thi\u1ebft dung t\u00edch c\u1ee7a c\u00e1c chi\u1ebfc gi\u1ecf \u0111\u1ee7 l\u1edbn \u0111\u1ec3 c\u00f3 th\u1ec3 x\u1ebfp s\u1ed1 l\u01b0\u1ee3ng b\u1ea5t k\u00ec c\u00e1c qu\u1ea3 t\u00e1o v\u00e0o gi\u1ecf, l\u00e0m th\u1ebf n\u00e0o x\u1ebfp 250 qu\u1ea3 t\u00e1o v\u00e0o t\u00e1m chi\u1ebfc gi\u1ecf m\u00e0 khi c\u1ea7n l\u1ea5y s\u1ed1 t\u00e1o b\u1ea5t k\u1ec3 l\u00e0 bao nhi\u00eau ta c\u0169ng kh\u00f4ng c\u1ea7n ph\u1ea3i \u0111\u1ebfm t\u1eebng qu\u1ea3 m\u00e0 ch\u1ec9 c\u1ea7n ch\u1ecdn s\u1ed1 gi\u1ecf l\u00e0 \u0111\u01b0\u1ee3c.<\/p>\n\n\n\n
V\u1eady ph\u1ea3i l\u00e0m th\u1ebf n\u00e0o? Suy ngh\u0129 k\u0129 m\u1ed9t ch\u00fat ta s\u1ebd th\u1ea5y th\u1ef1c ch\u1ea5t c\u1ee7a v\u1ea5n \u0111\u1ec1 nh\u01b0 sau: L\u00e0m th\u1ebf n\u00e0o chia 250 th\u00e0nh t\u00e1m s\u1ed1 t\u1ef1 nhi\u00ean t\u1eeb 1 \u0111\u1ebfn 250 sao cho c\u00f3 th\u1ec3 bi\u1ec3u di\u1ec5n s\u1ed1 250 b\u1eb1ng t\u1ed5ng c\u1ee7a t\u00e1m s\u1ed1 \u0111\u00f3.<\/p>\n\n\n\n
Tr\u01b0\u1edbc h\u1ebft ta \u0111\u00e1nh s\u1ed1 gi\u1ecf t\u1eeb , , ,\u2026, . Sau \u0111\u00f3 cho v\u00e0o gi\u1ecf s\u1ed1 qu\u1ea3 t\u00e1o t\u01b0\u01a1ng \u1ee9ng 1, 2, 4, 8, 16, 32, 64, 123, nh\u1edd \u0111\u00f3 ta c\u00f3 th\u1ec3 b\u1ecf to\u00e0n b\u1ed9 s\u1ed1 t\u00e1o v\u00e0o c\u00e1c gi\u1ecf. B\u00e2y gi\u1edd b\u1ea5t lu\u1eadn b\u1ea1n c\u1ea7n l\u1ea5y bao nhi\u00eau qu\u1ea3 t\u00e1o, b\u1ea1n ch\u1ec9 c\u1ea7n l\u1ea5y c\u00e1c s\u1ed1 gi\u1ecf th\u00edch h\u1ee3p m\u00e0 kh\u00f4ng c\u1ea7n \u0111\u1ebfm t\u1eebng qu\u1ea3. V\u00ed d\u1ee5 nh\u01b0 c\u1ea7n l\u1ea5y 55 qu\u1ea3, ta bi\u1ebft 55 = 32 + 16 + 4 + 2 + 1 v\u00e0 ta ch\u1ec9 c\u1ea7n l\u1ea5y c\u00e1c gi\u1ecf s\u1ed1 , , , , l\u00e0 \u0111\u1ee7 s\u1ed1 qu\u1ea3 t\u00e1o l\u00e0 55 m\u00e0 kh\u00f4ng c\u1ea7n \u0111\u1ebfm t\u1eebng qu\u1ea3 t\u00e1o. Kh\u00f4ng tin b\u1ea1n th\u1eed t\u00ednh v\u00e0 th\u1ea5y b\u1ea5t k\u00ec s\u1ed1 n\u00e0o t\u1eeb 1 \u0111\u1ebfn 250 \u0111\u1ec1u c\u00f3 th\u1ec3 ch\u1ecdn t\u1eeb t\u1ed5ng c\u00e1c s\u1ed1 kh\u00e1c nhau t\u1eeb t\u00e1m s\u1ed1 n\u00eau tr\u00ean.<\/p>\n\n\n\n
N\u1ebfu b\u1ea1n c\u1ea7n l\u1ea5y 255 qu\u1ea3 t\u00e1o th\u00ec \u0111\u01b0\u01a1ng nhi\u00ean ta ch\u1ec9 c\u00f3 m\u1ed9t \u0111\u00e1p \u00e1n l\u00e0:<\/p>\n\n\n\n
1 + 2 + 4 + 8 + 16 + 32 + 64 + 128 = 255.<\/p>\n\n\n\n
Th\u1ebf d\u00e3y s\u1ed1 tr\u00ean \u0111\u00e2y t\u1eeb \u0111\u00e2u m\u00e0 c\u00f3? \u0110\u1ec3 gi\u1ea3i \u0111\u00e1p c\u00e2u h\u1ecfi n\u00e0y ta c\u1ea7n quay l\u1ea1i c\u00e1ch ghi s\u1ed1 trong c\u00e1c h\u1ec7 \u0111\u1ebfm.<\/p>\n\n\n\n
Th\u00f4ng th\u01b0\u1eddng ng\u01b0\u1eddi ta ghi s\u1ed1 theo h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n g\u1ed3m 10 ch\u1eef s\u1ed1: 0, 1, 2,\u2026, 9. D\u00f9ng h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n ta c\u00f3 th\u1ec3 ghi l\u1ea1i b\u1ea5t k\u00ec s\u1ed1 t\u1ef1 nhi\u00ean n\u00e0o.<\/p>\n\n\n\n
Trong m\u00e1y t\u00ednh ng\u01b0\u1eddi ta l\u1ea1i d\u00f9ng c\u00e1ch ghi s\u1ed1 theo h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n. C\u00e1c ch\u1eef s\u1ed1 d\u00f9ng \u0111\u1ec3 ghi s\u1ed1 trong h\u1ec7 nh\u1ecb ph\u00e2n l\u00e0 hai ch\u1eef s\u1ed1 0 v\u00e0<\/p>\n\n\n\n
D\u00f9ng c\u00e1ch ghi s\u1ed1 theo h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n ng\u01b0\u1eddi ta c\u0169ng c\u00f3 th\u1ec3 ghi b\u1ea5t k\u00ec m\u1ed9t s\u1ed1 t\u1ef1 nhi\u00ean n\u00e0o.<\/p>\n\n\n\n
Ch\u00fang ta c\u00f3 th\u1ec3 theo quy t\u1eafc, chuy\u1ec3n c\u00e1ch ghi s\u1ed1 t\u1eeb h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n sang h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n v\u00e0 ng\u01b0\u1ee3c l\u1ea1i. V\u00ed d\u1ee5 s\u1ed1 55 l\u00e0 t\u1ed5ng c\u1ee7a c\u00e1c s\u1ed1 32, 16, 4, 2, 1 ghi theo h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n l\u00e0 110111. M\u00e0 s\u1ed1 110111 vi\u1ebft theo h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 10 l\u00e0 1 x 20 + 1 x 21 x 1 x 22 + 0 x 23 + 1 x 24 + 1 x 25 = 1 + 2 + 4 + 16 + 32 = 55<\/p>\n\n\n\n
B\u00e2y gi\u1edd ta \u0111\u00e3 th\u1ea5y r\u00f5 \u0111\u01b0\u1ee3c l\u00ed do c\u1ee7a \u0111\u00e1p \u00e1n tr\u00ean kia, v\u00ec c\u00e1ch chia 255 th\u00e0nh 8 s\u1ed1 20, 21, 22, 23, 24\u2026 nh\u1edd c\u00e1ch ph\u00e2n chia n\u00e0y, m\u1ed7i s\u1ed1 c\u1ee7a m\u1ed7i gi\u1ecf t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi m\u1ed9t v\u1ecb tr\u00ed trong c\u00e1ch ghi s\u1ed1 theo c\u01a1 s\u1ed1 hai g\u1ed3m hai ch\u1eef s\u1ed1 1 v\u00e0 0 v\u00e0 d\u1ef1a v\u00e0o \u0111\u00f3 m\u00e0 ch\u1ecdn hay kh\u00f4ng ch\u1ecdn. N\u1ebfu s\u1ed1 hi\u1ec7u c\u1ee7a c\u00e1c gi\u1ecf c\u00fang ch\u00ednh l\u00e0 s\u1ed1 v\u1ecb tr\u00ed c\u1ee7a c\u00e1c s\u1ed1 theo h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 hai t\u1eeb ph\u1ea3i sang tr\u00e1i v\u00ed d\u1ee5 55 th\u00ec t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi 110111 trong h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 2 t\u1ee9c l\u00e0 ch\u1ecdn c\u00e1c gi\u1ecf c\u00f3 s\u1ed1 th\u1ee9 t\u1ef1 1, 2, 3, 5 v\u00e0 6 ta s\u1ebd nh\u1eadn \u0111\u01b0\u1ee3c 55 qu\u1ea3 t\u00e1o nh\u01b0 \u0111\u00e1p \u00e1n \u0111\u00e3 n\u00eau. \u1ede \u0111\u00e2y ta kh\u00f4ng ch\u1ecdn gi\u1ecf s\u1ed1 b\u1ed1n v\u00ec theo c\u00e1ch ghi s\u1ed1 55 theo c\u01a1 s\u1ed1 hai, gi\u1ecf s\u1ed1 b\u1ed1n \u1edf v\u1ecb tr\u00ed c\u00f3 ch\u1eef s\u1ed1 0.<\/p>\n\n\n\n
T\u1eeb kho\u00e1: H\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 1; H\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 2.<\/p>\n\n\n\n
<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"
Trong b\u00e0n c\u1edd t\u01b0\u1edbng Trung Qu\u1ed1c con \u201cm\u00e3\u201d \u0111i theo quy t\u1eafc l\u00e0 nh\u1ea3y \u0111\u1ebfn \u0111\u1ec9nh \u0111\u1ed1i di\u1ec7n c\u1ee7a ch\u1eef nh\u1eadt. Li\u1ec7u con \u201cm\u00e3\u201d c\u00f3 th\u1ec3 \u0111i \u0111\u1ebfn v\u1ecb tr\u00ed b\u1ea5t k\u00ec tr\u00ean b\u00e0n c\u1edd kh\u00f4ng? C\u00e2u k\u1ebft lu\u1eadn l\u00e0 \u201cc\u00f3\u201d, c\u00f3 th\u1ec3 ch\u1ee9ng minh kh\u00e1 \u0111\u01a1n gi\u1ea3n. Hi\u1ec3n nhi\u00ean ch\u1ec9 c\u1ea7n con \u201cm\u00e3\u201d \u0111i […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[15,9],"tags":[],"class_list":["post-7573","post","type-post","status-publish","format-standard","hentry","category-hoi-dap-khoa-hoc","category-toan-hoc"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7573","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=7573"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7573\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=7573"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=7573"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=7573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}