{"segment":[{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" Cho c\u00e1c s\u1ed1 nguy\u00ean x, y th\u1ecfa m\u00e3n $\\dfrac{x}{2} = \\dfrac{3}{y}.$ \u0110\u00e1p \u00e1n n\u00e0o sau \u0111\u00e2y kh\u00f4ng ch\u00ednh x\u00e1c?","select":[" A. $x = 2; y = 3$ "," B. $x = -6; y = -1$","C. $ x= 2; y = -3$","D. $x = 1 ; y = 6$"],"hint":" Thay x, y v\u00e0o bi\u1ec3u th\u1ee9c $ \\dfrac{x}{2} = \\dfrac{y}{3}$ xem \u0111\u00e1p \u00e1n n\u00e0o kh\u00f4ng th\u1ecfa m\u00e3n","explain":" \u0110\u00e1p \u00e1n sai l\u00e0 C. <br\/> V\u00ec thay $ x= 2; y = -3$ v\u00e0o $\\dfrac{x}{2} = \\dfrac{3}{y}$ c\u00f3 <br\/> $\\dfrac{2}{2} = 1 \\neq \\dfrac{3}{-3} = -1$ <br\/> Thay $x, y$ \u1edf c\u00e1c ph\u01b0\u01a1ng \u00e1n A, B, D th\u1ea5y ch\u00fang th\u1ecfa m\u00e3n \u0111\u1eb3ng th\u1ee9c \u0111\u00e3 cho. <br\/> <span class='basic_pink'> V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":41},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":10,"ques":" Trong c\u00e1c ph\u00e2n s\u1ed1 sau, $ \\dfrac{-12}{15};\\dfrac{-15}{20};\\dfrac{-20}{28};\\dfrac{-27}{36} .$ Ph\u00e2n s\u1ed1 n\u00e0o bi\u1ec3u di\u1ec5n s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{3}{-4}?$ ","select":[" A. $\\dfrac{-12}{15}$ v\u00e0 $\\dfrac{-15}{20}$ "," B. $\\dfrac{-15}{20}$ v\u00e0 $\\dfrac{-20}{28}$"," C. $\\dfrac{-20}{28}$ v\u00e0 $\\dfrac{-27}{36}$","D. $\\dfrac{-15}{20}$ v\u00e0 $\\dfrac{-27}{36}$"],"hint":" R\u00fat g\u1ecdn ph\u00e2n s\u1ed1 v\u1ec1 d\u1ea1ng t\u1ed1i gi\u1ea3n r\u1ed3i so s\u00e1nh v\u1edbi $\\dfrac{3}{-4}$","explain":" \u00c1p d\u1ee5ng t\u00ednh ch\u1ea5t c\u01a1 b\u1ea3n c\u1ee7a ph\u00e2n s\u1ed1, ta c\u00f3: \\begin{align*} &\\dfrac{-12}{25} = \\dfrac{-4.3}{5.3} = \\dfrac{-4}{5} \\\\ &\\dfrac{-15}{20}= \\dfrac{3.(-5)}{-4.(-5)} = \\dfrac{-3}{4} = \\dfrac{3}{-4} \\\\ &\\dfrac{-20}{28} = \\dfrac{-5.4}{7.4} = \\dfrac{-5}{7} \\\\ &\\dfrac{-27}{36} = \\dfrac{3.(-9)}{-4.(-9)} = \\dfrac{3}{-4} \\\\ &\\text { V\u1eady c\u00e1c ph\u00e2n s\u1ed1 bi\u1ec3u di\u1ec5n s\u1ed1 h\u1eefu t\u1ec9 } \\dfrac{3}{-4}\\text { l\u00e0} : \\dfrac{-15}{20} \\text{ v\u00e0} \\dfrac{-27}{36} \\end{align*} <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span> ","column":2}]}],"id_ques":42},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" So s\u00e1nh n\u00e0o sau \u0111\u00e2y l\u00e0 sai?","select":["A. $\\dfrac{13}{15} < \\dfrac{33}{35}$","B. $\\dfrac{-9}{11} < \\dfrac{-5}{7}$","C. $\\dfrac{-9}{7} > \\dfrac{-19}{15}$"],"hint":" Quy \u0111\u1ed3ng m\u1eabu s\u1ed1 r\u1ed3i so s\u00e1nh","explain":" <span class='basic_left'> Ta c\u00f3: $\\bullet\\dfrac{13}{15} = \\dfrac{13.7}{15.7} = \\dfrac{91}{105}; \\qquad \\dfrac{33}{35} = \\dfrac{33.3}{35.3} = \\dfrac{99}{105} $ <br\/> M\u00e0 $91 < 99 $ n\u00ean $\\dfrac{91}{105} < \\dfrac{99}{105} \\Rightarrow \\dfrac{13}{15} < \\dfrac{33}{35} \\Rightarrow$ A \u0110\u00fang. <br\/> $\\bullet\\dfrac{-9}{11} = \\dfrac{-9.7}{11.7} = \\dfrac{-63}{77}; \\qquad \\dfrac{-5}{7} = \\dfrac{-5.11}{7.11} = \\dfrac{-55}{77} $ <br\/> M\u00e0 $-63 < -55 $ n\u00ean $\\dfrac{-63}{77} < \\dfrac{-55}{77} \\Rightarrow \\dfrac{-9}{11} < \\dfrac{-5}{7} \\Rightarrow$ B \u0110\u00fang. <br\/> $\\bullet\\dfrac{-9}{7} = \\dfrac{-9.15}{7.15} = \\dfrac{-135}{105}; \\qquad \\dfrac{-19}{15} = \\dfrac{-19.7}{15.7} = \\dfrac{-133}{105} $ <br\/> M\u00e0 $-135 < -133$ n\u00ean $\\dfrac{-135}{105} < \\dfrac{-133}{105} \\Rightarrow \\dfrac{-9}{7} < \\dfrac{-19}{15} \\Rightarrow$ C Sai. <\/span> <br\/> <br\/> <span class='basic_pink'> Ch\u1ecdn \u0111\u00e1p \u00e1n C. <\/span><\/span> ","column":3}]}],"id_ques":43},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":"","temp":"true_false","correct":[["t","f","t","f","f"]],"list":[{"point":10,"image":"","col_name":["","\u0110\u00fang","Sai"],"arr_ques":[" Gi\u1eefa hai s\u1ed1 h\u1eefu t\u1ec9 bao gi\u1edd c\u0169ng c\u00f3 m\u1ed9t s\u1ed1 h\u1eefu t\u1ec9"," T\u1eadp h\u1ee3p s\u1ed1 h\u1eefu t\u1ec9 k\u00ed hi\u1ec7u l\u00e0 $\\mathbb{R}$"," $ x > 0 \\Leftrightarrow x $ l\u00e0 s\u1ed1 h\u1eefu t\u1ec9 d\u01b0\u01a1ng"," $ x \\leq 0 \\Leftrightarrow x $ l\u00e0 s\u1ed1 h\u1eefu t\u1ec9 \u00e2m"," N\u1ebfu $ x < y $ th\u00ec tr\u00ean tr\u1ee5c s\u1ed1 \u0111i\u1ec3m x \u1edf b\u00ean ph\u1ea3i \u0111i\u1ec3m y"],"explain":" Gi\u1eefa hai s\u1ed1 h\u1eefu t\u1ec9 bao gi\u1edd c\u0169ng c\u00f3 m\u1ed9t s\u1ed1 h\u1eefu t\u1ec9. <br\/> $\\mathbb{Q}$ l\u00e0 t\u1eadp h\u1ee3p c\u00e1c s\u1ed1 h\u1eefu t\u1ec9, l\u00e0 s\u1ed1 \u0111\u01b0\u1ee3c vi\u1ebft d\u01b0\u1edbi d\u1ea1ng ph\u00e2n s\u1ed1 $\\dfrac{a}{b}$ v\u1edbi $a,b \u2208 \\mathbb{Z} , b \u2260 0$ <br\/> S\u1ed1 h\u1eefu t\u1ec9 \u00e2m < 0 < S\u1ed1 h\u1eefu t\u1ec9 d\u01b0\u01a1ng. <br\/> N\u1ebfu $ x < y $ th\u00ec tr\u00ean tr\u1ee5c s\u1ed1 \u0111i\u1ec3m x \u1edf b\u00ean tr\u00e1i \u0111i\u1ec3m y. <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111i\u1ec1n l\u00e0: \u0110\u00fang - Sai - \u0110\u00fang - Sai - Sai . <\/span><\/span> "}]}],"id_ques":44},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" C\u00f3 bao nhi\u00eau ph\u00e2n s\u1ed1 c\u00f3 m\u1eabu s\u1ed1 b\u1eb1ng 30, l\u1edbn h\u01a1n $\\dfrac{-2}{5}$ v\u00e0 nh\u1ecf h\u01a1n $\\dfrac{-1}{6} ? $ ","select":[" A. 4"," B. 5"," C. 6"," D. 7"],"explain":" <span class='basic_left'> G\u1ecdi ph\u00e2n s\u1ed1 ph\u1ea3i t\u00ecm l\u00e0 $\\dfrac{a}{30}; a \\in \\mathbb{Z}$ sao cho $\\dfrac{-2}{5} < \\dfrac{a}{30} < \\dfrac{-1}{6}$ <br\/> Quy \u0111\u1ed3ng m\u1eabu ta \u0111\u01b0\u1ee3c: $ \\dfrac{-12}{30} < \\dfrac{a}{30} < \\dfrac{-5}{30}$ <br\/> Suy ra $-12 < a < -5, $ v\u00ec $ a \\in \\mathbb{Z}$ n\u00ean $ a \\in \\lbrace -11; -10; -9; -8; -7 ;-6 \\rbrace$ <br\/> V\u1eady ta c\u00f3 6 ph\u00e2n s\u1ed1 th\u1ecfa m\u00e3n $\\dfrac{-2}{5} < \\dfrac{a}{30} < \\dfrac{-1}{6}$ l\u00e0 : $\\dfrac{-11}{30}; \\dfrac{-10}{30}; \\dfrac{-9}{30}; \\dfrac{-8}{30}; \\dfrac{-7}{30}; \\dfrac{-6}{30} $ <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":2}]}],"id_ques":45},{"time":24,"part":[{"title":"\u0110i\u1ec1n t\u1eeb th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["-6"],["0"],["2"],["8"]]],"list":[{"point":10,"width":50,"content":" T\u00ecm c\u00e1c s\u1ed1 nguy\u00ean $x \\left( x \\in \\mathbb{Z} \\right)$ \u0111\u1ec3: $N = \\dfrac{7}{x-1} \\in \\mathbb{Z}$","type_input":"","ques":"T\u1eadp h\u1ee3p X = { _input_ ; _input_ ; _input_ ; _input_} <br\/> (Vi\u1ebft k\u1ebft qu\u1ea3 theo th\u1ee9 t\u1ef1 t\u1eeb b\u00e9 \u0111\u1ebfn l\u1edbn)","hint":"S\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b}$ l\u00e0 s\u1ed1 nguy\u00ean khi b l\u00e0 \u01b0\u1edbc c\u1ee7a a.","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> b> T\u00ecm \u0111i\u1ec1u ki\u1ec7n \u0111\u1ec3 m\u1ed9t s\u1ed1 h\u1eefu t\u1ec9: l\u00e0 m\u1ed9t s\u1ed1 d\u01b0\u01a1ng, m\u1ed9t s\u1ed1 \u00e2m hay l\u00e0 m\u1ed9t s\u1ed1 nguy\u00ean <\/b> <br\/> <i> Ph\u01b0\u01a1ng ph\u00e1p gi\u1ea3i <\/i> <br\/> $\\bullet$ S\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b}$ l\u00e0 s\u1ed1 d\u01b0\u01a1ng n\u1ebfu $a$ v\u00e0 $ b$ c\u00f9ng d\u1ea5u; l\u00e0 s\u1ed1 \u00e2m n\u1ebfu $a$ v\u00e0 $ b$ kh\u00e1c d\u1ea5u; b\u1eb1ng $0$ n\u1ebfu $a$ b\u1eb1ng $0$ <br\/> $\\bullet$ Mu\u1ed1n cho s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b}$ l\u00e0 m\u1ed9t s\u1ed1 nguy\u00ean th\u00ec $b$ ph\u1ea3i l\u00e0 \u01b0\u1edbc c\u1ee7a $a$ <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> S\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b}$ l\u00e0 s\u1ed1 nguy\u00ean khi b l\u00e0 \u01b0\u1edbc c\u1ee7a a. <br\/>$N = \\dfrac{7}{x-1} \\in \\mathbb{Z} \\Leftrightarrow x - 1 \\text{ l\u00e0 \u01af(7)} \\text{ m\u00e0 \u01af(7)} = \\lbrace \\pm1; \\pm7 \\rbrace $ <br\/> Ta l\u1eadp b\u1ea3ng: <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop7/toan/daiso/bai1/lv3/img\/D7C11-K2-02.png' \/><\/center> <br\/> V\u1eady c\u00e1c s\u1ed1 nguy\u00ean $x$ th\u1ecfa m\u00e3n b\u00e0i to\u00e1n l\u00e0 $\\lbrace -6; 0; 2; 8 \\rbrace $<\/span> <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t l\u00e0: $-6; 0; 2; 8$ <\/span><\/span> "}]}],"id_ques":46},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":" So s\u00e1nh","temp":"true_false","correct":[["t","f","f","t"]],"list":[{"point":10,"image":"","ques":"","col_name":["","\u0110\u00fang","Sai"],"arr_ques":[" $\\dfrac{3}{12} = \\dfrac{-1}{-4}$"," $ \\dfrac{5}{9} = \\dfrac{7}{10}$"," $3 = \\dfrac{15}{4}$"," $\\dfrac{-26}{4} = \\dfrac{13}{-2}$"],"hint":" Ph\u01b0\u01a1ng ph\u00e1p nh\u00e2n ch\u00e9o.","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> C\u00e1c ph\u01b0\u01a1ng ph\u00e1p so s\u00e1nh hai s\u1ed1 h\u1eefu t\u1ec9 $\\dfrac{a}{b}$ v\u00e0 $\\dfrac{c}{d}, $ v\u1edbi $b,d > 0:$ <br\/> - So s\u00e1nh hai s\u1ed1 h\u1eefu t\u1ec9 b\u1eb1ng c\u00e1ch quy \u0111\u1ed3ng m\u1eabu ho\u1eb7c quy \u0111\u1ed3ng t\u1eed. <br\/> - So s\u00e1nh hai s\u1ed1 h\u1eefu t\u1ec9 kh\u00f4ng qua quy \u0111\u1ed3ng m\u1eabu ho\u1eb7c quy \u0111\u1ed3ng t\u1eed: <br\/> $\\quad $ + Ph\u01b0\u01a1ng ph\u00e1p nh\u00e2n ch\u00e9o: $\\dfrac{a}{b} > \\dfrac{c}{d} \\Leftrightarrow ad < bc$ v\u1edbi $b, d > 0.$ <br\/> $\\quad$ + So s\u00e1nh v\u1edbi m\u1ed9t s\u1ed1 h\u1eefu t\u1ec9 trung gian. <br\/> $\\quad$ + So s\u00e1nh v\u1edbi ph\u1ea7n b\u00f9 ( \u0111\u1ebfn \u0111\u01a1n v\u1ecb), so s\u00e1nh v\u1edbi ph\u1ea7n h\u01a1n ( so v\u1edbi \u0111\u01a1n v\u1ecb), ...<\/span> <br\/><br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> S\u1eed d\u1ee5ng ph\u01b0\u01a1ng ph\u00e1p nh\u00e2n ch\u00e9o ta \u0111\u01b0\u1ee3c: <br\/> $\\dfrac{3}{12} = \\dfrac{-1}{-4}$ v\u00ec $3.(-4) = 12.(-1) = -12$ <br\/>$ \\dfrac{5}{9} \\neq \\dfrac{7}{10}$ v\u00ec $ 5.10 \\neq 7.9 $ <br\/> $3 \\neq \\dfrac{15}{4}$ v\u00ec $3.4 \\neq 15.1 $ <br\/> $\\dfrac{-26}{4} = \\dfrac{13}{-2}$ v\u00ec $(-26)(-2) = 4.13 =52$ <\/span> <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111i\u1ec1n l\u00e0: \u0110\u00fang - Sai - Sai - \u0110\u00fang. <\/span><\/span> "}]}],"id_ques":47},{"time":24,"part":[{"title":"\u0110i\u1ec1n t\u1eeb th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["8"]]],"list":[{"point":10,"width":50,"type_input":"","ques":"T\u00ecm [x] bi\u1ebft: x - 0,7 < 8 < x ; [x] = _input_","hint":" Ph\u1ea7n nguy\u00ean c\u1ee7a m\u1ed9t s\u1ed1 h\u1eefu t\u1ec9 x, k\u00ed hi\u1ec7u l\u00e0 [x], l\u00e0 s\u1ed1 nguy\u00ean l\u1edbn nh\u1ea5t kh\u00f4ng v\u01b0\u1ee3t qu\u00e1 x.","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> N\u1ebfu s\u1ed1 h\u1eefu t\u1ec9 $x$ b\u1ecb k\u1eb9p gi\u1eefa hai s\u1ed1 nguy\u00ean li\u1ec1n nhau th\u00ec [x] \u0111\u00fang b\u1eb1ng s\u1ed1 nh\u1ecf nh\u1ea5t trong hai s\u1ed1 nguy\u00ean \u0111\u00f3. <br\/> N\u1ebfu $a < x < a + 1$ v\u1edbi $a \\in \\mathbb{Z} $ th\u00ec [x] = a <br\/> <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> V\u00ec $ x - 0,7 < 8 \\Rightarrow x < 8 + 0,7 = 8,7 < 9 $ <br\/> M\u1eb7t kh\u00e1c $x > 8$ <br\/> $\\Rightarrow 8 < x < 9 $ <br\/> N\u00ean [x] = 8. <\/span> <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111i\u1ec1n l\u00e0 8. <\/span><\/span> "}]}],"id_ques":48},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":" R\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c: <br\/> $ M = \\dfrac{a(b+1)-b-1}{b(a-1)+a-1} \\qquad ( a,b \\in \\mathbb{Q}; a \\neq 1; b \\neq -1 ) $","select":[" $M = 1$"," $ M = -1 $"," $M = \\dfrac{a}{b}$"," $ M = \\dfrac{b+1}{a-1} $"],"hint":" Bi\u1ebfn \u0111\u1ed5i t\u1eed s\u1ed1 v\u00e0 m\u1eabu s\u1ed1 r\u1ed3i r\u00fat g\u1ecdn. ","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> <b> \u0110\u1ecbnh ngh\u0129a <\/b> <br\/> S\u1ed1 h\u1eefu t\u1ec9 l\u00e0 s\u1ed1 \u0111\u01b0\u1ee3c vi\u1ebft d\u01b0\u1edbi d\u1ea1ng ph\u00e2n s\u1ed1 $\\dfrac{a}{b}$ v\u1edbi $a,b \u2208 \\mathbb{Z} , b \u2260 0$. <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: <br\/> $ M =\\dfrac{a(b+1)-b-1}{b(a-1)+a-1} \\\\ = \\dfrac{a(b+1) - (b+1)}{b(a-1)+(a-1)} \\\\ = \\dfrac{(b+1)(a-1)}{(b+1)(a-1)} \\\\ = 1 $ <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span> ","column":2}]}],"id_ques":49},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":10,"ques":" R\u00fat g\u1ecdn bi\u1ec3u th\u1ee9c: <br\/> $ M = \\dfrac{2a+2ab-b-1}{3b(2a-1)+6a-3} \\qquad ( a,b \\in \\mathbb{Q}; a \\neq \\dfrac{1}{2}; b \\neq -1 ) $","select":[" $M= \\dfrac{2a}{3b}$"," $M = \\dfrac{a}{b}$"," $ M = -1 $"," $ M = \\dfrac{1}{3} $"],"hint":" Bi\u1ebfn \u0111\u1ed5i t\u1eed s\u1ed1 v\u00e0 m\u1eabu s\u1ed1 r\u1ed3i r\u00fat g\u1ecdn. ","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> <b> \u0110\u1ecbnh ngh\u0129a <\/b> <br\/> S\u1ed1 h\u1eefu t\u1ec9 l\u00e0 s\u1ed1 \u0111\u01b0\u1ee3c vi\u1ebft d\u01b0\u1edbi d\u1ea1ng ph\u00e2n s\u1ed1 $\\dfrac{a}{b}$ v\u1edbi $a,b \u2208 \\mathbb{Z} , b \u2260 0$. <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: <br\/> $ M = \\dfrac{2a+2ab-b-1}{3b(2a-1)+6a-3} \\\\ = \\dfrac{2a(1+b) -(b+1)}{3b(2a-1)+3(2a-1)} \\\\ = \\dfrac{(2a-1)(b+1)}{(2a-1)(3b+3)} \\\\ = \\dfrac{(2a-1)(b+1)}{3(2a-1)(b+1)} \\\\ = \\dfrac{1}{3}$ <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span> ","column":2}]}],"id_ques":50}],"lesson":{"save":0,"level":3}}