{"id":7523,"date":"2021-11-20T13:58:08","date_gmt":"2021-11-20T06:58:08","guid":{"rendered":"https:\/\/www.vietlearn.org\/post\/?p=7523"},"modified":"2021-11-20T15:08:50","modified_gmt":"2021-11-20T08:08:50","slug":"ban-chon-tuy-y-bon-so-tu-nhien-lien-tiep-thanh-lap-tich-cua-chung-va-cong-them-1-khong-ke-ket-qua-phep-tinh-la-bao-nhieu-nhung-dieu-chac-chan-so-nhan-duoc-se-la-mot-chinh-phuong","status":"publish","type":"post","link":"https:\/\/www.vietlearn.org\/kien-thuc\/ban-chon-tuy-y-bon-so-tu-nhien-lien-tiep-thanh-lap-tich-cua-chung-va-cong-them-1-khong-ke-ket-qua-phep-tinh-la-bao-nhieu-nhung-dieu-chac-chan-so-nhan-duoc-se-la-mot-chinh-phuong\/","title":{"rendered":"B\u1ea1n ch\u1ecdn tu\u1ef3 \u00fd b\u1ed1n s\u1ed1 t\u1ef1 nhi\u00ean li\u00ean ti\u1ebfp, th\u00e0nh l\u1eadp t\u00edch c\u1ee7a ch\u00fang v\u00e0 c\u1ed9ng th\u00eam 1, kh\u00f4ng k\u1ec3 k\u1ebft qu\u1ea3 ph\u00e9p t\u00ednh l\u00e0 bao nhi\u00eau nh\u01b0ng \u0111i\u1ec1u ch\u1eafc ch\u1eafn s\u1ed1 nh\u1eadn \u0111\u01b0\u1ee3c s\u1ebd l\u00e0 m\u1ed9t ch\u00ednh ph\u01b0\u01a1ng."},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">B\u1ea1n c\u00f3 tin kh\u00f4ng? H\u00e3y xem c\u00e1c k\u1ebft qu\u1ea3 sau \u0111\u00e2y: 1.2.3.4 + 1 = 25 =52 2.3.4.5 + 1 = 121 = 112 3.4.5.6 + 1 = 361 = 192 4.5.6.7 + 1 = 841 = 292 \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">B\u1ea1n c\u00f3 th\u1ec3 ti\u1ebfp t\u1ee5c t\u00ednh to\u00e1n v\u00e0 k\u1ebft qu\u1ea3 t\u1ea5t y\u1ebfu s\u1ebd l\u00e0 c\u00e1c s\u1ed1 ch\u00ednh ph\u01b0\u01a1ng. V\u00ec sao l\u1ea1i nh\u1eadn \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 nh\u01b0 v\u1eady?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Gi\u1ea3 s\u1eed trong s\u1ed1 b\u1ed1n t\u1ef1 nhi\u00ean li\u00ean ti\u1ebfp ta ch\u1ecdn s\u1ed1 nh\u1ecf nh\u1ea5t l\u00e0 a, ta x\u00e9t xem t\u00edch s\u1ed1 sau \u0111\u00e2y c\u00f3 ph\u1ea3i l\u00e0 s\u1ed1 ch\u00ednh ph\u01b0\u01a1ng hay kh\u00f4ng: a(a + 1) (a + 2) (a + 3) + 1<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ta bi\u1ebft a(a + 1)(a + 2) (a + 3) + 1 = (a2 + 3a)(a2 + 3a + 2) + 1 = (a2 + 3a)2 +2(a2 + 3a) +1 = (a2 + 3a + 1)2<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ec a l\u00e0 s\u1ed1 t\u1ef1 nhi\u00ean n\u00ean (a2 + 3a + 1)2 ph\u1ea3i l\u00e0 m\u1ed9t ch\u00ednh ph\u01b0\u01a1ng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Th\u00f4ng qua ph\u00e9p d\u1eabn gi\u1ea3i tr\u00ean ta kh\u00f4ng ch\u1ec9 bi\u1ebft s\u1ed1 a(a + 1)(a + 2)(a +3 + 1) l\u00e0 m\u1ed9t ch\u00ednh ph\u01b0\u01a1ng m\u00e0 c\u00f2n bi\u1ebft s\u1ed1 ch\u00ednh ph\u01b0\u01a1ng l\u00e0 b\u00ecnh ph\u01b0\u01a1ng c\u1ee7a s\u1ed1 n\u00e0o?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ed d\u1ee5 10 x 11 x 12 x 13 = ?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Bi\u1ebft a = 10 n\u00ean a2 + 3a + 1 = 131 n\u00ean 10 x 11 x 12 x 13 + 1 =(131)2<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">T\u01b0\u01a1ng t\u1ef1 b\u1ea1n c\u0169ng c\u00f3 th\u1ec3 t\u00ecm th\u1ea5y 15 x 16 x 17 x 18 + 1 = ?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1edbi c\u00f9ng l\u00ed lu\u1eadn t\u01b0\u01a1ng t\u1ef1 b\u1ea1n c\u0169ng c\u00f3 th\u1ec3 t\u00ecm th\u1ea5y t\u00edch c\u1ee7a 4 s\u1ed1 ch\u1eb5n li\u00ean t\u1ee5c (4 s\u1ed1 l\u1ebb li\u00ean t\u1ee5c) c\u1ed9ng v\u1edbi 16 c\u0169ng l\u00e0 m\u1ed9t s\u1ed1 ch\u00ednh ph\u01b0\u01a1ng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">T\u1eeb kho\u00e1: S\u1ed1 ch\u00ednh ph\u01b0\u01a1ng ho\u00e0n to\u00e0n.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"<p>B\u1ea1n c\u00f3 tin kh\u00f4ng? H\u00e3y xem c\u00e1c k\u1ebft qu\u1ea3 sau \u0111\u00e2y: 1.2.3.4 + 1 = 25 =52 2.3.4.5 + 1 = 121 = 112 3.4.5.6 + 1 = 361 = 192 4.5.6.7 + 1 = 841 = 292 \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026. B\u1ea1n c\u00f3 th\u1ec3 ti\u1ebfp t\u1ee5c t\u00ednh to\u00e1n v\u00e0 k\u1ebft qu\u1ea3 t\u1ea5t y\u1ebfu s\u1ebd l\u00e0 c\u00e1c s\u1ed1 [&hellip;]<\/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-7523","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\/7523","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=7523"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7523\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=7523"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=7523"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=7523"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}