{"segment":[{"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":" <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/kiemtrachuong3/lv3/img\/2.jpg' \/><\/center>$\\dfrac{3}{10} . 5 +\\dfrac{11}{8} . \\dfrac{6}{22}$ = <span class='basic_hoi_black'>?<\/span>","select":["A. $\\dfrac{15}{8}$","B. $\\dfrac{7}{8}$","C. $\\dfrac{9}{8}$","D. $\\dfrac{10}{8}$"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Bi\u1ec3u th\u1ee9c ch\u1ee9a ph\u00e9p t\u00ednh nh\u00e2n v\u00e0 ph\u00e9p c\u1ed9ng, tr\u1eeb n\u00ean ta th\u1ef1c hi\u1ec7n t\u00ednh ph\u00e9p nh\u00e2n tr\u01b0\u1edbc, t\u00ednh ph\u00e9p c\u1ed9ng, tr\u1eeb sau.<\/span> <br\/><br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\dfrac{3}{10} . 5 +\\dfrac{11}{8} . \\dfrac{6}{22}$<br\/>= $\\dfrac{3}{2}+\\dfrac{3}{8}$<br\/>= $\\dfrac{12}{8}+\\dfrac{3}{8} $<br\/>= $\\dfrac{15}{8}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>A. $\\dfrac{15}{8}$<\/span><\/span> <br\/>","column":2}],"id_ques":1801},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/kiemtrachuong3/lv3/img\/2.jpg' \/><\/center>$\\dfrac{-5}{13} - (\\dfrac{3}{5} + \\dfrac{8}{13} - \\dfrac{4}{10})$ = <span class='basic_hoi_black'>?<\/span>","select":["A. $\\dfrac{-4}{5}$","B. $\\dfrac{4}{5}$","C. $\\dfrac{-6}{5}$","D. $\\dfrac{6}{5}$"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u1ecf ngo\u1eb7c r\u1ed3i nh\u00f3m c\u00e1c c\u1eb7p sao cho thu\u1eadn ti\u1ec7n \u0111\u1ec3 t\u00ednh.<\/span> <br\/><br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\dfrac{-5}{13} - (\\dfrac{3}{5} + \\dfrac{8}{13} - \\dfrac{4}{10})$<br\/>= $\\dfrac{-5}{13} - \\dfrac{3}{5} - \\dfrac{8}{13} + \\dfrac{4}{10}$ <br\/>= $(\\dfrac{-5}{13} - \\dfrac{8}{13})$ + $(\\dfrac{4}{10} - \\dfrac{3}{5})$<br\/>= $(\\dfrac{-5}{13} + \\dfrac{-8}{13})$ + $(\\dfrac{4}{10} - \\dfrac{6}{10})$<br\/>= $\\dfrac{-13}{13}$ + $\\dfrac{-2}{10}$<br\/>= -1 + $\\dfrac{-1}{5}$<br\/>= $\\dfrac{-5}{5}$ + $\\dfrac{-1}{5}$<br\/>= $\\dfrac{-6}{5}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>C. $\\dfrac{-6}{5}$<\/span><\/span> <br\/>","column":2}],"id_ques":1802},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":" T\u00ecm x, bi\u1ebft: x + $\\dfrac{-1}{3}$ = $\\dfrac{-5}{2}$","select":["A. x = $\\dfrac{-13}{6}$","B. x = $\\dfrac{-17}{6}$","C. x = $\\dfrac{13}{6}$","D. x = $\\dfrac{17}{6}$"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>x + $\\dfrac{-1}{3}$ = $\\dfrac{-5}{2}$<br\/>x = $\\dfrac{-5}{2}$ - $\\dfrac{-1}{3}$<br\/>x = $\\dfrac{-15}{6}$ + $\\dfrac{2}{6}$<br\/>x = $\\dfrac{-13}{6}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>A. x = $\\dfrac{-13}{6}$<\/span><\/span> <br\/>","column":2}],"id_ques":1803},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":" T\u00ecm x, bi\u1ebft: $\\dfrac{x}{4}$ -1 = $\\dfrac{7}{8}$ . $\\dfrac{16}{21}$","select":["A. x = $\\dfrac{20}{3}$","B. x = $\\dfrac{-20}{3}$","C. x = $\\dfrac{5}{12}$","D. x = $\\dfrac{-5}{12}$"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Ta c\u00f3 th\u1ec3 l\u00e0m nh\u01b0 sau:<br\/>+ B\u01b0\u1edbc 1: T\u00ednh v\u1ebf ph\u1ea3i<br\/>+ B\u01b0\u1edbc 2: T\u00ecm $\\dfrac{x}{4}$<br\/>+ B\u01b0\u1edbc 3: T\u00ecm x<\/span> <br\/><br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\dfrac{x}{4}$ -1 = $\\dfrac{7}{8}$ . $\\dfrac{16}{21}$<br\/>$\\dfrac{x}{4}$ -1 = $\\dfrac{2}{3}$<br\/>$\\dfrac{x}{4}$ = $\\dfrac{2}{3}$ + 1<br\/>$\\dfrac{x}{4}$ = $\\dfrac{2}{3}$ + $\\dfrac{3}{3}$<br\/>$\\dfrac{x}{4}$ = $\\dfrac{5}{3}$<br\/>x = $\\dfrac{4 . 5}{3}$<br\/>x = $\\dfrac{20}{3}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>A. x = $\\dfrac{20}{3}$<\/span><\/span> <br\/>","column":2}],"id_ques":1804},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":10,"ques":" $\\dfrac{1}{8}$ + $\\dfrac{3}{5}$ <span class='basic_hoi_black'>?<\/span> $\\dfrac{2}{5}$ + $\\dfrac{1}{4}$","select":["A. <","B. >","C. ="],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>B\u01b0\u1edbc 1: T\u00ednh k\u1ebft qu\u1ea3 c\u1ee7a t\u1eebng v\u1ebf<br\/>B\u01b0\u1edbc 2: So s\u00e1nh k\u1ebft qu\u1ea3 v\u1eeba t\u00ecm \u1edf b\u01b0\u1edbc 1<\/span> <br\/><br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>$\\dfrac{1}{8}$ + $\\dfrac{3}{5}$ = $\\dfrac{5}{40}$ + $\\dfrac{24}{40}$ = $\\dfrac{29}{40}$<br\/>$\\dfrac{2}{5}$ + $\\dfrac{1}{4}$ = $\\dfrac{8}{20}$ + $\\dfrac{5}{20}$ = $\\dfrac{13}{20}$ = $\\dfrac{26}{40}$<br\/>M\u00e0 $\\dfrac{26}{40}$ <b> < <\/b> $\\dfrac{29}{40}$<br\/>N\u00ean $\\dfrac{1}{8}$ + $\\dfrac{3}{5}$ > $\\dfrac{2}{5}$ + $\\dfrac{1}{4}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>B. ><\/span><\/span> <br\/><\/span>","column":3}],"id_ques":1805},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" T\u00ecm x, bi\u1ebft: $x^2$ = $\\dfrac{16}{25}$","select":["A. x = $\\dfrac{4}{5}$","B. x = $\\dfrac{-4}{5}$","C. x = $\\dfrac{4}{5}$ ho\u1eb7c x = $\\dfrac{-4}{5}$","D. x = $\\dfrac{16}{25}$"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3:<br\/>$\\dfrac{16}{25}$ = $\\left(\\begin{array}{c} \\dfrac{4}{5}\\end{array}\\right)^{2}$ = $\\left(\\begin{array}{c} \\dfrac{-4}{5}\\end{array}\\right)^{2}$<br\/>Suy ra x = $\\dfrac{4}{5}$ ho\u1eb7c x = $\\dfrac{-4}{5}$ <br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>C. x = $\\dfrac{4}{5}$ ho\u1eb7c x = $\\dfrac{-4}{5}$<\/span><\/span> <br\/>","column":2}],"id_ques":1806},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":" T\u1ec9 s\u1ed1 c\u1ee7a hai s\u1ed1 a v\u00e0 b l\u00e0 $1\\dfrac{1}{5}$. T\u1ed5ng c\u1ee7a hai s\u1ed1 \u0111\u00f3 l\u00e0 44. Hai s\u1ed1 a, b l\u00e0:","select":["A. a = 24, b = 20","B. a = 20, b = 24","C. a = 18, b = 26","D. a = 26, b = 18"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: \u0110\u01b0a t\u1ec9 s\u1ed1 c\u1ee7a hai s\u1ed1 a v\u00e0 b v\u1ec1 d\u1ea1ng ph\u00e2n s\u1ed1<br\/> B\u01b0\u1edbc 2: T\u00ecm a, b<\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>T\u1ec9 s\u1ed1 c\u1ee7a hai s\u1ed1 a v\u00e0 b l\u00e0 $1\\dfrac{1}{5}$<br\/> N\u00ean $\\dfrac{a}{b}$ = $1\\dfrac{1}{5}$ = $\\dfrac{6}{5}$<br\/>Suy ra $\\dfrac{a}{a + b}$ = $\\dfrac{6}{6 + 5}$ = $\\dfrac{6}{11}$<br\/>M\u00e0 a + b = 44<br\/>Do \u0111\u00f3 $\\dfrac{a}{44}$ = $\\dfrac{6}{11}$ suy ra a = $\\dfrac{6 . 44}{11}$ = 24<br\/>b = 44 - 24 = 20<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>A. a = 24, b = 20<\/span><\/span> <br\/><\/span><span class='basic_left'><span class='basic_green'>Nh\u1eadn x\u00e9t: <\/span>$\\dfrac{a}{b}$ = $\\dfrac{c}{d}$ suy ra <b>a . d = b . c<\/b> do \u0111\u00f3 <b>a<\/b> = $\\dfrac{b . c}{d}$<\/span>","column":2}],"id_ques":1807},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" T\u1ec9 s\u1ed1 c\u1ee7a hai s\u1ed1 a v\u00e0 b l\u00e0 50%. Hi\u1ec7u c\u1ee7a hai s\u1ed1 \u0111\u00f3 l\u00e0 6. Hai s\u1ed1 a, b l\u00e0:","select":["A. a = 7, b = 13","B. a = 4, b = 10","C. a = 6, b = 12","D. a = 5, b = 7"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: \u0110\u01b0a t\u1ec9 s\u1ed1 c\u1ee7a hai s\u1ed1 a v\u00e0 b v\u1ec1 d\u1ea1ng ph\u00e2n s\u1ed1 t\u1ed1i gi\u1ea3n<br\/> B\u01b0\u1edbc 2: T\u00ecm a<br\/> B\u01b0\u1edbc 3: T\u00ecm b<\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>T\u1ec9 s\u1ed1 c\u1ee7a hai s\u1ed1 a v\u00e0 b l\u00e0 50%<br\/> N\u00ean $\\dfrac{a}{b}$ = 50% = $\\dfrac{1}{2}$ v\u00e0 b > a<br\/>Suy ra $\\dfrac{a}{b - a}$ = $\\dfrac{1}{2 - 1}$ = 1<br\/>M\u00e0 b - a = 6<br\/>Do \u0111\u00f3 $\\dfrac{a}{6}$ = 1 suy ra a = 6 . 1 = 6<br\/>b - a = 6 suy ra b = 6 + a = 6 + 6 = 12<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>C. a = 6, b = 12<\/span><\/span> <br\/><\/span>","column":2}],"id_ques":1808},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":10,"ques":" H\u00e3y ch\u1ecdn kh\u1eb3ng \u0111\u1ecbnh \u0111\u00fang:","select":["A. $\\dfrac{-4}{7}$ > $\\dfrac{-4}{-7}$","B. $\\dfrac{-5}{8}$ < $\\dfrac{5}{-8}$","C. $\\dfrac{-2}{-5}$ = $\\dfrac{-2}{5}$","D. $\\dfrac{-11}{10}$ < 0"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>$\\dfrac{-4}{-7}$ = $\\dfrac{4}{7}$ > $\\dfrac{-4}{7}$<br\/>$\\dfrac{-5}{8}$ = $\\dfrac{5}{-8}$<br\/> $\\dfrac{-2}{-5}$ = $\\dfrac{2}{5}$ > $\\dfrac{-2}{5}$<br\/> $\\dfrac{-11}{10}$ < 0<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>D.<\/span> $\\dfrac{-11}{10}$ < 0<br\/><\/span>","column":2}],"id_ques":1809},{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" T\u00ednh t\u1ed5ng:<br\/>C = $\\dfrac{1}{2.4} + \\dfrac{1}{4.6}+ \\dfrac{1}{6.8} + ... + \\dfrac{1}{2008.2010}$","select":["C = $\\dfrac{502}{1005}$","C = $\\dfrac{500}{1005}$","C = $\\dfrac{251}{1005}$","C = $\\dfrac{1004}{1005}$"],"hint":"$\\dfrac{1}{2.4}$ = $\\dfrac{1}{2}$($\\dfrac{1}{2}$ - $\\dfrac{1}{4}$)","explain":" <span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>C = $\\dfrac{1}{2.4} + \\dfrac{1}{4.6}+ \\dfrac{1}{6.8} + ... + \\dfrac{1}{2008.2010}$<br\/>C = $\\dfrac{1}{2}$. $\\left( \\dfrac{2}{2.4} + \\dfrac{2}{4.6}+ \\dfrac{2}{6.8} + ... + \\dfrac{2}{2008.2010}\\right)$<br\/>C = $\\dfrac{1}{2}$. $\\left(\\dfrac{1}{2} - \\dfrac{1}{4} + \\dfrac{1}{4} - \\dfrac{1}{6} + \\dfrac{1}{6} - \\dfrac{1}{8} + ... - \\dfrac{1}{2008} + \\dfrac{1}{2008} - \\dfrac{1}{2010} \\right)$<br\/>C = $\\dfrac{1}{2}$. $\\left[ \\dfrac{1}{2} + \\left( \\dfrac{-1}{4} + \\dfrac{1}{4} \\right) + \\left(\\dfrac{-1}{6} + \\dfrac{1}{6}\\right) + \\left(\\dfrac{-1}{8} + \\dfrac{1}{8} \\right) + ... + \\left(\\dfrac{-1}{2008} + \\dfrac{1}{2008} \\right) - \\dfrac{1}{2010}\\right]$<br\/>C = $\\dfrac{1}{2}$. $\\left( \\dfrac{1}{2} + 0 + 0 + 0 + ... + 0 - \\dfrac{1}{2010} \\right)$<br\/>C = $\\dfrac{1}{2}$. $\\left(\\dfrac{1}{2} - \\dfrac{1}{2010} \\right)$<br\/>C = $\\dfrac{1}{2}$. $\\left(\\dfrac{1005}{2010} - \\dfrac{1}{2010}\\right)$<br\/>C = $\\dfrac{1}{2}$. $\\dfrac{1004}{2010}$<br\/>C = $\\dfrac{251}{1005}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>C = $\\dfrac{251}{1005}$<\/span><\/span> <br\/><\/span><span class='basic_left'><span class='basic_green'>Nh\u1eadn x\u00e9t: <\/span>$\\dfrac{2}{n.(n + 2)}$ = $\\dfrac{1}{n}$ - $\\dfrac{1}{n + 2}$, v\u1edbi n $\\in$ Z, n $\\ne $ -2<\/span>","column":2}],"id_ques":1810}],"id_ques":0}],"lesson":{"save":1,"level":3,"time":44}}