{"common":{"save":0,"post_id":"4665","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7301","post_id":"4665","mon_id":"1158113","chapter_id":"1158164","question":"<p>Lan dùng m\u1ed9t cái th\u01b0\u1edbc th\u1eb3ng dài kho\u1ea3ng <strong>53 cm<\/strong> \u0111\u1ec3 \u0111o chi\u1ec1u r\u1ed9ng c\u1ee7a n\u1ec1n nhà mình. Sau <strong>15 l\u1ea7n<\/strong> \u0111o liên ti\u1ebfp thì \u0111\u1ea7u th\u01b0\u1edbc và mép t\u01b0\u1eddng còn cách nhau kho\u1ea3ng <strong>25 cm<\/strong>. H\u1ecfi <strong>chi\u1ec1u r\u1ed9ng <\/strong>c\u1ee7a n\u1ec1n nhà Lan kho\u1ea3ng <strong>bao nhiêu mét<\/strong>?<\/p>","options":["820 m","82 m","8,2 m","0,82 m"],"correct":"3","level":"3","hint":"","answer":"<p>Vì sau 15 l\u1ea7n \u0111o liên ti\u1ebfp thì \u0111\u1ea7u th\u01b0\u1edbc và mép t\u01b0\u1eddng còn cách nhau kho\u1ea3ng 25 cm nên chi\u1ec1u r\u1ed9ng c\u1ee7a n\u1ec1n nhà là:<\/p><p>53 . 15 + 25 = 795 + 25 = 820 cm = <span class=\"frac123\"><span class=\"ts\">820<\/span><span class=\"ms\">100<\/span><\/span> m = <span style=\"color:#16a085;\"><strong>8,2 m<\/strong><\/span><\/p><p>V\u1eady n\u1ec1n nhà Lan r\u1ed9ng kho\u1ea3ng <span style=\"color:#16a085;\"><strong>8,2 m<\/strong><\/span>.<\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"><strong>8,2 m<\/strong><\/span>.<\/p>","type":"choose","extra_type":"cloud","time":"0","user_id":"131","test":"1","date":"2021-09-06 12:26:36","option_type":"txt","len":0},{"id":"7303","post_id":"4665","mon_id":"1158113","chapter_id":"1158164","question":"<p>Cho ba \u0111i\u1ec3m th\u1eb3ng hàng M, N, P. Bi\u1ebft MN = MP + PN. H\u1ecfi trong ba \u0111i\u1ec3m M, N, P, <strong>\u0111i\u1ec3m nào n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m còn l\u1ea1i<\/strong>?<\/p>","options":["\u0110i\u1ec3m M","\u0110i\u1ec3m N","\u0110i\u1ec3m P"],"correct":"3","level":"3","hint":"","answer":"<p>Cho ba \u0111i\u1ec3m th\u1eb3ng hàng M, N, P. Ta có 3 tr\u01b0\u1eddng h\u1ee3p x\u1ea3y ra: <\/p><p> N\u1ebfu M n\u1eb1m gi\u1eefa N và P thì NP = NM + MP.<\/p><p> N\u1ebfu N n\u1eb1m gi\u1eefa M và P thì MP = MN + NP. <\/p><p> N\u1ebfu <span style=\"color:#16a085;\">P n\u1eb1m gi\u1eefa M và N<\/span> thì <strong>MN = MP + PN <\/strong>(\u0111úng v\u1edbi h\u1ec7 th\u1ee9c \u0111\u1ec1 cho)<\/p><p>V\u1eady MN = MP + PN thì <span style=\"color:#16a085;\">P n\u1eb1m gi\u1eefa M và N<\/span>.<\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"><strong>\u0110i\u1ec3m P<\/strong><\/span><\/p>","type":"choose","extra_type":"shape1","time":"0","user_id":"131","test":"3","date":"2021-09-06 12:38:24","option_type":"txt","len":0},{"id":"7307","post_id":"4665","mon_id":"1158113","chapter_id":"1158164","question":"<p>Trên \u0111o\u1ea1n th\u1eb3ng MN dài 35 cm, l\u1ea5y \u0111i\u1ec3m E sao cho \u0111o\u1ea1n th\u1eb3ng ME dài h\u01a1n \u0111o\u1ea1n th\u1eb3ng NE 12 cm. Tính \u0111\u1ed9 dài c\u1ee7a các \u0111o\u1ea1n th\u1eb3ng ME và NE.<\/p>","options":["ME = 23,5 cm ; NE = 11,5 cm","ME = 11,5 cm ; NE = 23,5 cm","ME = 24,5 cm ; NE = 12,5 cm","ME = 20,5 cm ; NE = 11,5 cm"],"correct":"1","level":"3","hint":"","answer":"<p>Vì \u0111i\u1ec3m E n\u1eb1m trên \u0111o\u1ea1n th\u1eb3ng MN nên E n\u1eb1m gi\u1eefa hai \u0111i\u1ec3m M và N.<\/p><p>Suy ra MN = ME + EN hay ME + EN = 35 (1) <\/p><p>M\u1eb7t khác, ME dài h\u01a1n NE 12 cm nên ME - NE = 12 hay ME = 12 + NE (2)<\/p><p>Thay (2) vào (1), ta \u0111\u01b0\u1ee3c 12 + NE + NE = 35 hay 12 + 2 . NE = 35<\/p><p> 2 . NE = 35 - 12<\/p><p> 2 . NE = 23<\/p><p> <span style=\"color:#16a085;\">NE = 23 : 2 = 11,5 (cm)<\/span><\/p><p>Mà <span style=\"color:#16a085;\">ME = 12 + NE = 12 + 11,5 = 23,5 (cm)<\/span><\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"><strong>ME = 23,5 cm ; NE = 11,5 cm<\/strong><\/span><\/p><p> <\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2021-09-06 13:06:39","option_type":"txt","len":2}]}