{"id":567268,"date":"2026-07-23T09:55:01","date_gmt":"2026-07-23T02:55:01","guid":{"rendered":"https:\/\/hoanghamobile.com\/tin-tuc\/?p=567268"},"modified":"2026-07-23T09:55:01","modified_gmt":"2026-07-23T02:55:01","slug":"cach-tim-bcnn","status":"publish","type":"post","link":"https:\/\/hoanghamobile.com\/tin-tuc\/cach-tim-bcnn\/","title":{"rendered":"C\u00e1ch t\u00ecm BCNN (b\u1ed9i chung nh\u1ecf nh\u1ea5t) nhanh v\u00e0 ch\u00ednh x\u00e1c"},"content":{"rendered":"

C\u00e1ch t\u00ecm BCNN (b\u1ed9i chung nh\u1ecf nh\u1ea5t) <\/b>c\u1ee7a hai hay nhi\u1ec1u s\u1ed1 \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n b\u1eb1ng c\u00e1ch ph\u00e2n t\u00edch m\u1ed7i s\u1ed1 ra th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1, r\u1ed3i ch\u1ecdn c\u00e1c th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 chung v\u00e0 ri\u00eang, m\u1ed7i th\u1eeba s\u1ed1 l\u1ea5y v\u1edbi s\u1ed1 m\u0169 l\u1edbn nh\u1ea5t v\u00e0 nh\u00e2n ch\u00fang l\u1ea1i v\u1edbi nhau. \u0110\u00e2y l\u00e0 m\u1ed9t k\u1ef9 n\u0103ng n\u1ec1n t\u1ea3ng c\u1ee7a To\u00e1n l\u1edbp 6, xu\u1ea5t hi\u1ec7n th\u01b0\u1eddng xuy\u00ean khi b\u1ea1n quy \u0111\u1ed3ng m\u1eabu s\u1ed1 ph\u00e2n s\u1ed1 hay gi\u1ea3i c\u00e1c b\u00e0i to\u00e1n v\u1ec1 chu k\u1ef3. N\u1ebfu n\u1eafm ch\u1eafc quy t\u1eafc, b\u1ea1n c\u00f3 th\u1ec3 t\u00ecm ra k\u1ebft qu\u1ea3 ch\u1ec9 trong v\u00e0i b\u01b0\u1edbc ng\u1eafn g\u1ecdn v\u00e0 h\u1ea1n ch\u1ebf t\u1ed1i \u0111a nh\u1ea7m l\u1eabn.<\/span><\/p>\n

BCNN l\u00e0 g\u00ec?<\/b><\/h2>\n

B\u1ed9i chung nh\u1ecf nh\u1ea5t c\u1ee7a hai hay nhi\u1ec1u s\u1ed1 l\u00e0 s\u1ed1 nh\u1ecf nh\u1ea5t kh\u00e1c 0 trong t\u1eadp h\u1ee3p c\u00e1c b\u1ed9i chung c\u1ee7a c\u00e1c s\u1ed1 \u0111\u00f3, k\u00fd hi\u1ec7u BCNN(a, b). N\u00f3i c\u00e1ch kh\u00e1c, \u0111\u00f3 l\u00e0 s\u1ed1 b\u00e9 nh\u1ea5t (kh\u00e1c 0) m\u00e0 t\u1ea5t c\u1ea3 c\u00e1c s\u1ed1 \u0111\u00e3 cho \u0111\u1ec1u chia h\u1ebft. V\u00ed d\u1ee5, b\u1ed9i c\u1ee7a 4 l\u00e0 0, 4, 8, 12, 16, 20, 24\u2026; b\u1ed9i c\u1ee7a 6 l\u00e0 0, 6, 12, 18, 24\u2026; c\u00e1c b\u1ed9i chung c\u1ee7a 4 v\u00e0 6 l\u00e0 12, 24, 36\u2026, n\u00ean BCNN(4, 6) = 12. \u0110\u00e2y ch\u00ednh l\u00e0 s\u1ed1 nh\u1ecf nh\u1ea5t m\u00e0 c\u1ea3 4 v\u00e0 6 c\u00f9ng chia h\u1ebft.<\/span><\/p>\n

\"cach-tim-bcnn-1\"<\/p>\n

C\u00e1ch t\u00ecm BCNN nh\u01b0 th\u1ebf n\u00e0o?<\/b><\/h2>\n

C\u00e1ch ph\u1ed5 bi\u1ebfn v\u00e0 ch\u00ednh x\u00e1c nh\u1ea5t \u0111\u1ec3 t\u00ecm b\u1ed9i chung nh\u1ecf nh\u1ea5t l\u00e0 ph\u00e2n t\u00edch c\u00e1c s\u1ed1 ra th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 r\u1ed3i gh\u00e9p l\u1ea1i theo quy t\u1eafc. Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y gi\u00fap b\u1ea1n x\u00e1c \u0111\u1ecbnh nhanh gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t chia h\u1ebft cho t\u1ea5t c\u1ea3 c\u00e1c s\u1ed1 \u0111\u00e3 cho v\u00e0 \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng r\u1ed9ng r\u00e3i trong c\u00e1c b\u00e0i to\u00e1n v\u1ec1 ph\u00e2n s\u1ed1, chia h\u1ebft v\u00e0 t\u00ecm chu k\u1ef3. B\u1ea1n ch\u1ec9 c\u1ea7n th\u1ef1c hi\u1ec7n tu\u1ea7n t\u1ef1 ba b\u01b0\u1edbc c\u01a1 b\u1ea3n d\u01b0\u1edbi \u0111\u00e2y.<\/span><\/p>\n

    \n
  • B\u01b0\u1edbc 1: Ph\u00e2n t\u00edch m\u1ed7i s\u1ed1 ra th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1.<\/span><\/li>\n
  • B\u01b0\u1edbc 2: Ch\u1ecdn ra c\u00e1c th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 chung v\u00e0 ri\u00eang c\u1ee7a c\u00e1c s\u1ed1.<\/span><\/li>\n
  • B\u01b0\u1edbc 3: L\u1eadp t\u00edch c\u00e1c th\u1eeba s\u1ed1 \u0111\u00e3 ch\u1ecdn, m\u1ed7i th\u1eeba s\u1ed1 l\u1ea5y v\u1edbi s\u1ed1 m\u0169 l\u1edbn nh\u1ea5t. T\u00edch \u0111\u00f3 l\u00e0 BCNN c\u1ea7n t\u00ecm.<\/span><\/li>\n<\/ul>\n

    L\u01b0u \u00fd nh\u1ecf: n\u1ebfu trong c\u00e1c s\u1ed1 \u0111\u00e3 cho c\u00f3 s\u1ed1 b\u1eb1ng 1 th\u00ec b\u1ecf qua n\u00f3, v\u00ec BCNN(a, 1) = a. Ngo\u00e0i ra, n\u1ebfu s\u1ed1 l\u1edbn nh\u1ea5t \u0111\u00e3 chia h\u1ebft cho t\u1ea5t c\u1ea3 c\u00e1c s\u1ed1 c\u00f2n l\u1ea1i th\u00ec ch\u00ednh s\u1ed1 l\u1edbn nh\u1ea5t \u0111\u00f3 l\u00e0 BCNN, b\u1ea1n kh\u00f4ng c\u1ea7n ph\u00e2n t\u00edch th\u00eam.<\/span><\/p>\n

    V\u00ed d\u1ee5 minh h\u1ecda c\u00f3 l\u1eddi gi\u1ea3i t\u1eebng b\u01b0\u1edbc<\/b><\/h2>\n

    C\u00e1ch t\u1ed1t nh\u1ea5t \u0111\u1ec3 hi\u1ec3u quy t\u1eafc l\u00e0 theo d\u00f5i m\u1ed9t v\u00ed d\u1ee5 \u0111\u01b0\u1ee3c gi\u1ea3i chi ti\u1ebft t\u1eebng b\u01b0\u1edbc. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 hai tr\u01b0\u1eddng h\u1ee3p: t\u00ecm BCNN c\u1ee7a hai s\u1ed1 v\u00e0 c\u1ee7a ba s\u1ed1.<\/span><\/p>\n

    V\u00ed d\u1ee5 1 \u2013 T\u00ecm BCNN(12, 18):<\/b><\/p>\n

      \n
    • B\u01b0\u1edbc 1 \u2013 Ph\u00e2n t\u00edch ra th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1: 12 = 2\u00b2 \u00d7 3; 18 = 2 \u00d7 3\u00b2.<\/span><\/li>\n
    • B\u01b0\u1edbc 2 \u2013 Th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 chung v\u00e0 ri\u00eang g\u1ed3m: 2 v\u00e0 3.<\/span><\/li>\n
    • B\u01b0\u1edbc 3 \u2013 L\u1ea5y m\u1ed7i th\u1eeba s\u1ed1 v\u1edbi s\u1ed1 m\u0169 l\u1edbn nh\u1ea5t: 2\u00b2 (l\u1edbn h\u01a1n 2\u00b9) v\u00e0 3\u00b2 (l\u1edbn h\u01a1n 3\u00b9).<\/span><\/li>\n
    • K\u1ebft qu\u1ea3: BCNN(12, 18) = 2\u00b2 \u00d7 3\u00b2 = 4 \u00d7 9 = 36.<\/span><\/li>\n<\/ul>\n

      V\u00ed d\u1ee5 2 \u2013 T\u00ecm BCNN(8, 12, 15):<\/b><\/p>\n

        \n
      • B\u01b0\u1edbc 1 \u2013 Ph\u00e2n t\u00edch: 8 = 2\u00b3; 12 = 2\u00b2 \u00d7 3; 15 = 3 \u00d7 5.<\/span><\/li>\n
      • B\u01b0\u1edbc 2 \u2013 C\u00e1c th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 xu\u1ea5t hi\u1ec7n: 2, 3 v\u00e0 5.<\/span><\/li>\n
      • B\u01b0\u1edbc 3 \u2013 L\u1ea5y s\u1ed1 m\u0169 l\u1edbn nh\u1ea5t c\u1ee7a t\u1eebng th\u1eeba s\u1ed1: 2\u00b3, 3\u00b9 v\u00e0 5\u00b9.<\/span><\/li>\n
      • K\u1ebft qu\u1ea3: BCNN(8, 12, 15) = 2\u00b3 \u00d7 3 \u00d7 5 = 8 \u00d7 3 \u00d7 5 = 120.<\/span><\/li>\n<\/ul>\n

        \"cach-tim-bcnn-4\"<\/p>\n

        C\u00e1ch t\u00ecm BCNN b\u1eb1ng ph\u01b0\u01a1ng ph\u00e1p li\u1ec7t k\u00ea b\u1ed9i<\/b><\/h2>\n

        V\u1edbi c\u00e1c s\u1ed1 nh\u1ecf, b\u1ea1n c\u00f3 th\u1ec3 t\u00ecm BCNN b\u1eb1ng c\u00e1ch li\u1ec7t k\u00ea b\u1ed9i m\u00e0 kh\u00f4ng c\u1ea7n ph\u00e2n t\u00edch th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1. C\u00e1ch l\u00e0m l\u00e0 vi\u1ebft l\u1ea7n l\u01b0\u1ee3t c\u00e1c b\u1ed9i c\u1ee7a t\u1eebng s\u1ed1, r\u1ed3i t\u00ecm s\u1ed1 nh\u1ecf nh\u1ea5t kh\u00e1c 0 xu\u1ea5t hi\u1ec7n chung \u1edf t\u1ea5t c\u1ea3 c\u00e1c danh s\u00e1ch.<\/span><\/p>\n

        V\u00ed d\u1ee5 t\u00ecm BCNN(4, 6): b\u1ed9i c\u1ee7a 4 l\u00e0 4, 8, 12, 16, 20, 24\u2026; b\u1ed9i c\u1ee7a 6 l\u00e0 6, 12, 18, 24\u2026. S\u1ed1 nh\u1ecf nh\u1ea5t kh\u00e1c 0 xu\u1ea5t hi\u1ec7n \u1edf c\u1ea3 hai d\u00e3y l\u00e0 12, v\u1eady BCNN(4, 6) = 12. Ph\u01b0\u01a1ng ph\u00e1p li\u1ec7t k\u00ea tr\u1ef1c quan v\u00e0 d\u1ec5 hi\u1ec3u, nh\u01b0ng s\u1ebd ch\u1eadm v\u00e0 d\u1ec5 sai v\u1edbi c\u00e1c s\u1ed1 l\u1edbn, n\u00ean khi l\u00e0m b\u00e0i ki\u1ec3m tra b\u1ea1n v\u1eabn n\u00ean \u01b0u ti\u00ean ph\u00e2n t\u00edch ra th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1.<\/span><\/p>\n

        Quan h\u1ec7 gi\u1eefa BCNN v\u00e0 \u01afCLN<\/b><\/h2>\n

        BCNN v\u00e0 \u01afCLN g\u1eafn v\u1edbi nhau qua m\u1ed9t c\u00f4ng th\u1ee9c r\u1ea5t h\u1eefu \u00edch. V\u1edbi hai s\u1ed1 nguy\u00ean d\u01b0\u01a1ng a v\u00e0 b, t\u00edch c\u1ee7a ch\u00fang b\u1eb1ng t\u00edch c\u1ee7a \u01b0\u1edbc chung l\u1edbn nh\u1ea5t v\u00e0 b\u1ed9i chung nh\u1ecf nh\u1ea5t:<\/span> a \u00d7 b = \u01afCLN(a, b) \u00d7 BCNN(a, b)<\/b>.<\/span><\/p>\n

        Nh\u1edd c\u00f4ng th\u1ee9c n\u00e0y, n\u1ebfu \u0111\u00e3 bi\u1ebft \u01afCLN th\u00ec b\u1ea1n suy ra BCNN r\u1ea5t nhanh: BCNN(a, b) = (a \u00d7 b) \/ \u01afCLN(a, b). V\u00ed d\u1ee5, \u01afCLN(12, 18) = 6 n\u00ean BCNN(12, 18) = (12 \u00d7 18) \/ 6 = 216 \/ 6 = 36 \u2013 tr\u00f9ng kh\u1edbp v\u1edbi k\u1ebft qu\u1ea3 t\u00ecm b\u1eb1ng c\u00e1ch ph\u00e2n t\u00edch th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 \u1edf tr\u00ean. L\u01b0u \u00fd c\u00f4ng th\u1ee9c n\u00e0y ch\u1ec9 \u0111\u00fang g\u1ecdn g\u00e0ng cho tr\u01b0\u1eddng h\u1ee3p hai s\u1ed1; v\u1edbi ba s\u1ed1 tr\u1edf l\u00ean, b\u1ea1n n\u00ean d\u00f9ng c\u00e1ch ph\u00e2n t\u00edch th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1.<\/span><\/p>\n

        Ph\u00e2n bi\u1ec7t BCNN v\u00e0 \u01afCLN<\/b><\/h2>\n

        Nhi\u1ec1u h\u1ecdc sinh th\u01b0\u1eddng nh\u1ea7m l\u1eabn gi\u1eefa hai kh\u00e1i ni\u1ec7m n\u00e0y v\u00ec c\u00f9ng d\u1ef1a tr\u00ean ph\u00e2n t\u00edch th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1. \u0110i\u1ec3m kh\u00e1c bi\u1ec7t c\u1ed1t l\u00f5i n\u1eb1m \u1edf ch\u1ed7 ch\u1ecdn th\u1eeba s\u1ed1 v\u00e0 s\u1ed1 m\u0169. B\u1ea3ng d\u01b0\u1edbi \u0111\u00e2y t\u00f3m t\u1eaft \u0111\u1ec3 b\u1ea1n d\u1ec5 so s\u00e1nh.<\/span><\/p>\n\n\n\n\n\n\n\n\n
        Ti\u00eau ch\u00ed<\/th>\n\u01afCLN (\u01af\u1edbc chung l\u1edbn nh\u1ea5t)<\/th>\nBCNN (B\u1ed9i chung nh\u1ecf nh\u1ea5t)<\/th>\n<\/tr>\n<\/thead>\n
        \u00dd ngh\u0129a<\/td>\nS\u1ed1 l\u1edbn nh\u1ea5t m\u00e0 c\u1ea3 hai s\u1ed1 c\u00f9ng chia h\u1ebft<\/td>\nS\u1ed1 nh\u1ecf nh\u1ea5t kh\u00e1c 0 m\u00e0 c\u1ea3 hai s\u1ed1 c\u00f9ng chia h\u1ebft cho n\u00f3<\/td>\n<\/tr>\n
        Ch\u1ecdn th\u1eeba s\u1ed1<\/td>\nCh\u1ec9 l\u1ea5y th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 chung<\/td>\nL\u1ea5y c\u1ea3 th\u1eeba s\u1ed1 chung v\u00e0 ri\u00eang<\/td>\n<\/tr>\n
        S\u1ed1 m\u0169<\/td>\nL\u1ea5y s\u1ed1 m\u0169 nh\u1ecf nh\u1ea5t<\/td>\nL\u1ea5y s\u1ed1 m\u0169 l\u1edbn nh\u1ea5t<\/td>\n<\/tr>\n
        V\u00ed d\u1ee5 v\u1edbi 12 v\u00e0 18<\/td>\n\u01afCLN = 2 \u00d7 3 = 6<\/td>\nBCNN = 2\u00b2 \u00d7 3\u00b2 = 36<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

        M\u1ed9t m\u1eb9o d\u1ec5 nh\u1edb l\u00e0: “\u01afCLN l\u1ea5y s\u1ed1 m\u0169 nh\u1ecf nh\u1ea5t, BCNN l\u1ea5y s\u1ed1 m\u0169 l\u1edbn nh\u1ea5t”. Ch\u1ec9 c\u1ea7n nh\u1edb quy t\u1eafc n\u00e0y, b\u1ea1n s\u1ebd h\u1ea1n ch\u1ebf \u0111\u01b0\u1ee3c ph\u1ea7n l\u1edbn nh\u1ea7m l\u1eabn khi l\u00e0m b\u00e0i.<\/span><\/p>\n

        \"cach-tim-bcnn-2\"<\/p>\n

        \u1ee8ng d\u1ee5ng c\u1ee7a BCNN<\/b><\/h2>\n

        BCNN c\u00f3 nhi\u1ec1u \u1ee9ng d\u1ee5ng thi\u1ebft th\u1ef1c trong h\u1ecdc t\u1eadp v\u00e0 \u0111\u1eddi s\u1ed1ng. \u1ee8ng d\u1ee5ng ph\u1ed5 bi\u1ebfn nh\u1ea5t l\u00e0 quy \u0111\u1ed3ng m\u1eabu s\u1ed1 c\u00e1c ph\u00e2n s\u1ed1, trong \u0111\u00f3 m\u1eabu s\u1ed1 chung nh\u1ecf nh\u1ea5t ch\u00ednh l\u00e0 BCNN c\u1ee7a c\u00e1c m\u1eabu s\u1ed1, gi\u00fap ph\u00e9p t\u00ednh g\u1ecdn g\u00e0ng h\u01a1n.<\/span><\/p>\n

        B\u00ean c\u1ea1nh \u0111\u00f3, BCNN c\u00f2n \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 gi\u1ea3i c\u00e1c b\u00e0i to\u00e1n v\u1ec1 chu k\u1ef3 l\u1eb7p l\u1ea1i, ch\u1eb3ng h\u1ea1n x\u00e1c \u0111\u1ecbnh th\u1eddi \u0111i\u1ec3m hai xe c\u00f9ng xu\u1ea5t ph\u00e1t s\u1ebd g\u1eb7p l\u1ea1i nhau, ho\u1eb7c khi nhi\u1ec1u s\u1ef1 ki\u1ec7n di\u1ec5n ra \u0111\u1ed3ng th\u1eddi sau m\u1ed9t kho\u1ea3ng th\u1eddi gian nh\u1ea5t \u0111\u1ecbnh. \u0110\u00e2y l\u00e0 d\u1ea1ng b\u00e0i r\u1ea5t hay g\u1eb7p trong \u0111\u1ec1 thi l\u1edbp 6.<\/span><\/p>\n

        Ngo\u00e0i ra, BCNN c\u0169ng xu\u1ea5t hi\u1ec7n trong c\u00e1c b\u00e0i to\u00e1n x\u1ebfp nh\u00f3m, chia th\u00e0nh c\u00e1c ph\u1ea7n \u0111\u1ec1u nhau ho\u1eb7c s\u1eafp x\u1ebfp \u0111\u1ed1i t\u01b0\u1ee3ng theo quy lu\u1eadt, gi\u00fap b\u1ea1n t\u00ecm \u0111\u01b0\u1ee3c ph\u01b0\u01a1ng \u00e1n ph\u00f9 h\u1ee3p v\u00e0 t\u1ed1i \u01b0u.<\/span><\/p>\n

        Nh\u1eefng l\u1ed7i th\u01b0\u1eddng g\u1eb7p khi t\u00ecm BCNN<\/b><\/h2>\n

        Khi m\u1edbi h\u1ecdc, h\u1ecdc sinh r\u1ea5t d\u1ec5 m\u1eafc m\u1ed9t s\u1ed1 l\u1ed7i khi\u1ebfn k\u1ebft qu\u1ea3 sai l\u1ec7ch. Nh\u1eadn di\u1ec7n tr\u01b0\u1edbc nh\u1eefng l\u1ed7i n\u00e0y s\u1ebd gi\u00fap b\u1ea1n l\u00e0m b\u00e0i ch\u1eafc ch\u1eafn h\u01a1n.<\/span><\/p>\n

          \n
        • L\u1ea5y nh\u1ea7m s\u1ed1 m\u0169 nh\u1ecf nh\u1ea5t (quy t\u1eafc c\u1ee7a \u01afCLN) thay v\u00ec s\u1ed1 m\u0169 l\u1edbn nh\u1ea5t khi t\u00ecm BCNN.<\/span><\/li>\n
        • B\u1ecf s\u00f3t th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 ri\u00eang, ch\u1ec9 nh\u00e2n c\u00e1c th\u1eeba s\u1ed1 chung n\u00ean k\u1ebft qu\u1ea3 b\u1ecb thi\u1ebfu.<\/span><\/li>\n
        • Ph\u00e2n t\u00edch th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 sai, v\u00ed d\u1ee5 vi\u1ebft 12 = 2 \u00d7 6 (v\u00ec 6 ch\u01b0a ph\u1ea3i s\u1ed1 nguy\u00ean t\u1ed1) thay v\u00ec 12 = 2\u00b2 \u00d7 3.<\/span><\/li>\n
        • \u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c BCNN = a \u00d7 b \/ \u01afCLN cho ba s\u1ed1 tr\u1edf l\u00ean, d\u1eabn \u0111\u1ebfn k\u1ebft qu\u1ea3 kh\u00f4ng ch\u00ednh x\u00e1c.<\/span><\/li>\n
        • Qu\u00ean r\u1eb1ng BCNN ph\u1ea3i kh\u00e1c 0, nh\u1ea7m l\u1eabn gi\u1eefa “b\u1ed9i chung nh\u1ecf nh\u1ea5t” v\u1edbi s\u1ed1 0.<\/span><\/li>\n<\/ul>\n

          B\u00e0i t\u1eadp v\u1eadn d\u1ee5ng c\u00f3 l\u1eddi gi\u1ea3i<\/b><\/h2>\n

          H\u00e3y th\u1eed t\u1ef1 l\u00e0m r\u1ed3i \u0111\u1ed1i chi\u1ebfu v\u1edbi l\u1eddi gi\u1ea3i \u0111\u1ec3 c\u1ee7ng c\u1ed1 c\u00e1ch t\u00ecm BCNN.<\/span><\/p>\n

          B\u00e0i 1: T\u00ecm BCNN(6, 8). L\u1eddi gi\u1ea3i: 6 = 2 \u00d7 3; 8 = 2\u00b3; BCNN = 2\u00b3 \u00d7 3 = 24.<\/span><\/p>\n

          B\u00e0i 2: T\u00ecm BCNN(10, 15). L\u1eddi gi\u1ea3i: 10 = 2 \u00d7 5; 15 = 3 \u00d7 5; BCNN = 2 \u00d7 3 \u00d7 5 = 30.<\/span><\/p>\n

          B\u00e0i 3: Bi\u1ebft \u01afCLN(24, 36) = 12, t\u00ednh BCNN(24, 36). L\u1eddi gi\u1ea3i: BCNN = (24 \u00d7 36) \/ 12 = 864 \/ 12 = 72.<\/span><\/p>\n

          B\u00e0i 4: Quy \u0111\u1ed3ng hai ph\u00e2n s\u1ed1 1\/4 v\u00e0 1\/6. L\u1eddi gi\u1ea3i: BCNN(4, 6) = 12, n\u00ean 1\/4 = 3\/12 v\u00e0 1\/6 = 2\/12.<\/span><\/p>\n

          B\u00e0i 5 (tr\u1eafc nghi\u1ec7m): BCNN(4, 6) b\u1eb1ng bao nhi\u00eau? A. 2 B. 12 C. 24 D. 10. \u0110\u00e1p \u00e1n: B.<\/span><\/p>\n

          \"cach-tim-bcnn-3\"<\/p>\n

          C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p v\u1ec1 c\u00e1ch t\u00ecm BCNN<\/b><\/h2>\n

          BCNN l\u00e0 g\u00ec?<\/b><\/h3>\n

          BCNN l\u00e0 s\u1ed1 nh\u1ecf nh\u1ea5t kh\u00e1c 0 trong t\u1eadp h\u1ee3p c\u00e1c b\u1ed9i chung c\u1ee7a hai hay nhi\u1ec1u s\u1ed1, t\u1ee9c s\u1ed1 b\u00e9 nh\u1ea5t m\u00e0 t\u1ea5t c\u1ea3 c\u00e1c s\u1ed1 \u0111\u00e3 cho \u0111\u1ec1u chia h\u1ebft.<\/span><\/p>\n

          C\u00e1ch t\u00ecm BCNN g\u1ed3m m\u1ea5y b\u01b0\u1edbc?<\/b><\/h3>\n

          G\u1ed3m ba b\u01b0\u1edbc: ph\u00e2n t\u00edch m\u1ed7i s\u1ed1 ra th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1, ch\u1ecdn c\u00e1c th\u1eeba s\u1ed1 chung v\u00e0 ri\u00eang, r\u1ed3i nh\u00e2n ch\u00fang v\u1edbi s\u1ed1 m\u0169 l\u1edbn nh\u1ea5t.<\/span><\/p>\n

          BCNN(12, 18) b\u1eb1ng bao nhi\u00eau?<\/b><\/h3>\n

          B\u1eb1ng 36, v\u00ec 12 = 2\u00b2 \u00d7 3, 18 = 2 \u00d7 3\u00b2, n\u00ean BCNN = 2\u00b2 \u00d7 3\u00b2 = 36.<\/span><\/p>\n

          Quan h\u1ec7 gi\u1eefa BCNN v\u00e0 \u01afCLN l\u00e0 g\u00ec?<\/b><\/h3>\n

          V\u1edbi hai s\u1ed1 a v\u00e0 b: a \u00d7 b = \u01afCLN(a, b) \u00d7 BCNN(a, b), n\u00ean BCNN b\u1eb1ng t\u00edch hai s\u1ed1 chia cho \u01afCLN.<\/span><\/p>\n

          C\u00f3 th\u1ec3 t\u00ecm BCNN m\u00e0 kh\u00f4ng c\u1ea7n ph\u00e2n t\u00edch th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 kh\u00f4ng?<\/b><\/h3>\n

          C\u00f3, v\u1edbi c\u00e1c s\u1ed1 nh\u1ecf b\u1ea1n c\u00f3 th\u1ec3 li\u1ec7t k\u00ea b\u1ed9i c\u1ee7a t\u1eebng s\u1ed1 r\u1ed3i ch\u1ecdn s\u1ed1 chung nh\u1ecf nh\u1ea5t kh\u00e1c 0, nh\u01b0ng c\u00e1ch n\u00e0y ch\u1eadm v\u00e0 d\u1ec5 sai v\u1edbi s\u1ed1 l\u1edbn.<\/span><\/p>\n

          BCNN d\u00f9ng \u0111\u1ec3 l\u00e0m g\u00ec?<\/b><\/h3>\n

          BCNN d\u00f9ng \u0111\u1ec3 quy \u0111\u1ed3ng m\u1eabu s\u1ed1 ph\u00e2n s\u1ed1 v\u00e0 gi\u1ea3i c\u00e1c b\u00e0i to\u00e1n v\u1ec1 chu k\u1ef3 l\u1eb7p l\u1ea1i, chia nh\u00f3m \u0111\u1ec1u nhau.<\/span><\/p>\n

          K\u1ebft lu\u1eadn<\/b><\/h2>\n

          T\u00f3m l\u1ea1i, <\/span>c\u00e1ch t\u00ecm BCNN <\/b>l\u00e0 ph\u00e2n t\u00edch c\u00e1c s\u1ed1 ra th\u1eeba s\u1ed1 nguy\u00ean t\u1ed1 r\u1ed3i nh\u00e2n c\u00e1c th\u1eeba s\u1ed1 chung v\u00e0 ri\u00eang v\u1edbi s\u1ed1 m\u0169 l\u1edbn nh\u1ea5t, ho\u1eb7c d\u00f9ng c\u00f4ng th\u1ee9c BCNN = (a \u00d7 b) \/ \u01afCLN cho hai s\u1ed1. N\u1eafm v\u1eefng k\u1ef9 n\u0103ng n\u00e0y gi\u00fap b\u1ea1n quy \u0111\u1ed3ng m\u1eabu s\u1ed1 v\u00e0 x\u1eed l\u00fd nhi\u1ec1u d\u1ea1ng to\u00e1n s\u1ed1 h\u1ecdc m\u1ed9t c\u00e1ch nh\u1eb9 nh\u00e0ng. \u0110\u1ec3 h\u1ecdc th\u00eam, m\u1eddi b\u1ea1n tham kh\u1ea3o c\u00e1c b\u00e0i<\/span> t\u1eadp h\u1ee3p s\u1ed1 nguy\u00ean Z l\u00e0 g\u00ec<\/span><\/a>,<\/span> kh\u00e1i ni\u1ec7m v\u00e0 \u1ee9ng d\u1ee5ng c\u1ee7a s\u1ed1 nguy\u00ean<\/span><\/a> v\u00e0<\/span> c\u00f4ng th\u1ee9c t\u1ed5 h\u1ee3p, ch\u1ec9nh h\u1ee3p<\/span><\/a> tr\u00ean chuy\u00ean m\u1ee5c tin t\u1ee9c c\u1ee7a Ho\u00e0ng H\u00e0 Mobile. <\/span><\/p>\n

          Xem th\u00eam:<\/b><\/p>\n

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            Ph\u01b0\u01a1ng tr\u00ecnh l\u01b0\u1ee3ng gi\u00e1c c\u01a1 b\u1ea3n: c\u00f4ng th\u1ee9c nghi\u1ec7m v\u00e0 v\u00ed d\u1ee5<\/a><\/p>\n<\/li>\n

          • \n

            Gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i l\u00e0 g\u00ec? T\u00ednh ch\u1ea5t v\u00e0 c\u00e1ch gi\u1ea3i b\u00e0i t\u1eadp<\/a><\/p>\n<\/li>\n<\/ul>\n