{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["3"],["11"]]],"list":[{"point":10,"width":50,"type_input":"","ques":" Cho $A = \\sqrt{x+2} + \\dfrac{3}{11}.$ T\u00ecm gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t c\u1ee7a $A$. <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> Min A = <div class=\"frac123\"><div class=\"ts\">_input_<\/div><div class=\"ms\">_input_<\/div><\/div>","hint":" \u00c1p d\u1ee5ng: $A \\geq m $ suy ra $min A = m $","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> - T\u00ecm $x$ \u0111\u1ec3 A c\u00f3 ngh\u0129a. <br\/> - \u00c1p d\u1ee5ng: $A \\geq m $ suy ra min A = m <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> A c\u00f3 ngh\u0129a khi $x + 2 \\geq 0 \\Rightarrow x \\geq -2$ <br\/> V\u1edbi $x \\geq -2 $ th\u00ec $\\sqrt{x+2} \\geq 0 $ <br\/> Suy ra $ \\sqrt{x+2} + \\dfrac{3}{11} \\geq \\dfrac{3}{11}$ <br\/> V\u1eady gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t c\u1ee7a $ A = \\dfrac{3}{11}$ khi $x+2 = 0 $ hay $x = - 2$ <br\/> <br\/> <span class='basic_pink'> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0 $\\dfrac{3}{11}$ khi $x = -2 $ <\/span><\/span>"}]}],"id_ques":441},{"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":" T\u00ecm s\u1ed1 nguy\u00ean $x$ \u0111\u1ec3 $B = \\dfrac{\\sqrt{x} - 3}{\\sqrt{x} + 2}$ c\u00f3 gi\u00e1 tr\u1ecb l\u00e0 m\u1ed9t s\u1ed1 nguy\u00ean.","select":["A. $x = 9 $ ","B. $x \\in \\{ -1; 9 \\} $ ","C. $x \\in \\{ -1; 9; 49 \\} $ ","D. $x \\in \\{ 1; 9 \\} $ "],"hint":" \u0110\u1ec3 $\\dfrac{a}{b}$ l\u00e0 s\u1ed1 nguy\u00ean th\u00ec $b$ ph\u1ea3i l\u00e0 \u01b0\u1edbc c\u1ee7a $a$","explain":" <span class='basic_left'><span class='basic_green'> B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $B = \\dfrac{\\sqrt{x} - 3}{\\sqrt{x} + 2} \\\\ = \\dfrac{\\sqrt{x}+2-5}{\\sqrt{x}+2} = 1 - \\dfrac{5}{\\sqrt{x}+2}$ <br\/> \u0110\u1ec3 $ B \\in \\mathbb{Z}$ th\u00ec ($\\sqrt{x} + 2$) ph\u1ea3i thu\u1ed9c $\\mathbb{Z}$ v\u00e0 l\u00e0 \u01af(5) = $\\{ \\pm1; \\pm 5 \\}$ <br\/> V\u00ec $\\sqrt{x} + 2 > 0$ n\u00ean ch\u1ec9 c\u00f3 hai tr\u01b0\u1eddng h\u1ee3p: <br\/> Tr\u01b0\u1eddng h\u1ee3p 1: $\\sqrt{x} + 2 = 1 \\Leftrightarrow \\sqrt{x} = -1 \\Rightarrow$ kh\u00f4ng c\u00f3 x th\u1ecfa m\u00e3n. <br\/> Tr\u01b0\u1eddng h\u1ee3p 2: $\\sqrt{x} + 2 = 5 \\Leftrightarrow \\sqrt{x} = 3 \\Rightarrow x = 9$ (th\u1ecfa m\u00e3n). <br\/> V\u1eady \u0111\u1ec3 $B \\in \\mathbb{Z}$ th\u00ec $x = 9 $<br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span> ","column":2}]}],"id_ques":442},{"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":" T\u00ecm $x$, bi\u1ebft $\\sqrt{1,69} . \\left(2\\sqrt{x} + \\sqrt{\\dfrac{81}{121}} \\right) = \\dfrac{13}{10}?$ ","select":["A. $x = \\dfrac{9}{11}$ ","B. $x = \\dfrac{1}{11}$ ","C. $x = \\dfrac{2}{11}$","D. $x = \\dfrac{1}{121}$"],"explain":" <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> $\\sqrt{1,69} . \\left(2\\sqrt{x} + \\sqrt{\\dfrac{81}{121}} \\right) = \\dfrac{13}{10} \\\\ \\Leftrightarrow 1,3 . \\left(2\\sqrt{x} + \\dfrac{9}{11}\\right) = 1,3 \\\\ \\Leftrightarrow 2\\sqrt{x} + \\dfrac{9}{11} = 1 \\\\ \\Leftrightarrow 2\\sqrt{x} = 1 - \\dfrac{9}{11} = \\dfrac{2}{11} \\\\ \\Leftrightarrow \\sqrt{x} = \\dfrac{2}{11} : 2 = \\dfrac{1}{11} \\\\ \\Leftrightarrow x = \\left(\\dfrac{1}{11}\\right)^{2} = \\dfrac{1}{121} $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 D. <\/span><\/span> ","column":2}]}],"id_ques":443},{"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":" T\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c sau: <br\/> $ A = \\left[-\\sqrt{2,25} + 4.\\sqrt{(-2,15)^{2}} - \\left(3.\\sqrt{\\dfrac{7}{6}}\\right)^{2}\\right].\\sqrt{1\\dfrac{9}{16}} $ ","select":["A. -4,25 ","B. -25,75 ","C. -3,4 ","D. -5,6 "],"explain":" $ A = \\left[-\\sqrt{2,25} + 4.\\sqrt{(-2,15)^{2}} - \\left(3.\\sqrt{\\dfrac{7}{6}}\\right)^{2}\\right].\\sqrt{1\\dfrac{9}{16}} \\\\ = \\left[ -1,5 + 4.2,15 - 3^{2}.\\left(\\sqrt{\\dfrac{7}{6}}\\right)^{2} \\right] . \\sqrt{\\dfrac{25}{16}} \\\\ = \\left( -1,5 + 8,6 - 9.\\dfrac{7}{6} \\right) . \\dfrac{5}{4} \\\\ = (7,1 - 10,5).\\dfrac{5}{4} \\\\ = -3,4 . \\dfrac{5}{4} \\\\ = -4,25 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 A. <\/span><\/span> ","column":4}]}],"id_ques":444},{"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":" T\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c sau: <br\/> $ B = \\sqrt{\\dfrac{361}{10^{6}}}.\\left[\\dfrac{3}{2}.\\sqrt{(-10)^{8}} - 30.\\sqrt{\\dfrac{2.10^{5}}{5}} \\right]$ ","select":["A. 399 ","B. 1710 ","C. 171 ","D. 361 "],"explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span> <br\/> - \u0110\u01b0a c\u00e1c c\u0103n b\u1eadc hai v\u1ec1 d\u1ea1ng $\\sqrt{a^{2}} = a $ <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> $ B = \\sqrt{\\dfrac{361}{10^{6}}}.\\left[\\dfrac{3}{2}.\\sqrt{(-10)^{8}} - 30.\\sqrt{\\dfrac{2.10^{5}}{5}} \\right] \\\\ = \\sqrt{\\left(\\dfrac{19}{10^{3}}\\right)^{2}}.\\left[\\dfrac{3}{2}.\\sqrt{(-10^{4})^{2}} - 30.\\sqrt{40000} \\right]\\\\ = \\dfrac{19}{10^{3}}.\\left( \\dfrac{3}{2} . 10^{4} - 30 . 200 \\right) \\\\ = \\dfrac{19}{10^{3}}.(15000 - 6000) \\\\ =\\dfrac{19}{10^{3}}.9000 \\\\ = 19.9 \\\\ = 171 $ <br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":4}]}],"id_ques":445},{"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 s\u1ed1 nguy\u00ean sau khi l\u00e0m tr\u00f2n \u0111\u1ebfn ch\u1eef s\u1ed1 h\u00e0ng tr\u0103m cho k\u1ebft qu\u1ea3 l\u00e0 3500? ","select":["A. 90 ","B. 95","C. 100","D. 101"],"hint":" Xem quy \u01b0\u1edbc l\u00e0m tr\u00f2n s\u1ed1. ","explain":" <span class='basic_left'><span class='basic_green'><\/span> <br\/> <\/span> <br\/> <br\/> <span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> S\u1ed1 nguy\u00ean l\u1edbn nh\u1ea5t l\u00e0m tr\u00f2n tr\u0103m th\u00e0nh 3500 l\u00e0 s\u1ed1 3549. <br\/> S\u1ed1 nguy\u00ean nh\u1ecf nh\u1ea5t l\u00e0m tr\u00f2n tr\u0103m th\u00e0nh 3500 l\u00e0 s\u1ed1 3450. <br\/> Do \u0111\u00f3 s\u1ed1 nguy\u00ean l\u00e0m tr\u00f2n tr\u0103m th\u00e0nh 3500 l\u00e0: <br\/> 3549 - 3450 + 1 = 100 (s\u1ed1)<br\/> <br\/> <span class='basic_pink'> \u0110\u00e1p \u00e1n \u0111\u00fang l\u00e0 C. <\/span><\/span> ","column":4}]}],"id_ques":446},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["2,1"]]],"list":[{"point":10,"width":50,"type_input":"","ques":" T\u00ecm $x$ trong t\u1ec9 l\u1ec7 th\u1ee9c $ 8,5 : x = 3,7 : 0,9$ <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> $x \\approx $ _input_<br\/>(L\u00e0m tr\u00f2n k\u1ebft qu\u1ea3 \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 nh\u1ea5t)","explain":" <span class='basic_left'><span class='basic_green'><\/span> <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Ta c\u00f3: $8,5 : x = 3,7 : 0,9 $ <br\/> Suy ra: $x = \\dfrac{8,5.0,9}{3,7}$ <br\/> $x = 2,0675...$ <br\/> $\\approx 2,1$ (l\u00e0m tr\u00f2n \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 nh\u1ea5t)<br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 l\u00e0 2,1 <\/span><\/span>"}]}],"id_ques":447},{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["71500"]]],"list":[{"point":10,"width":90,"type_input":"","ques":" M\u1ed9t s\u1ed1 nguy\u00ean sau khi l\u00e0m tr\u00f2n \u0111\u1ebfn h\u00e0ng ngh\u00ecn th\u00ec \u0111\u01b0\u1ee3c 72 000. H\u1ecfi s\u1ed1 \u0111\u00f3 nh\u1ecf nh\u1ea5t l\u00e0 bao nhi\u00eau? <br\/> <b> \u0110\u00e1p s\u1ed1: <\/b> _input_","hint":" Xem quy \u01b0\u1edbc l\u00e0m tr\u00f2n s\u1ed1 ","explain":" <span class='basic_left'><span class='basic_green'><\/span> <\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> S\u1ed1 nh\u1ecf nh\u1ea5t l\u00e0m tr\u00f2n \u0111\u1ebfn h\u00e0ng ngh\u00ecn th\u00e0nh 72 000 l\u00e0 s\u1ed1 71 500 <br\/> <br\/> <span class='basic_pink'> K\u1ebft qu\u1ea3 l\u00e0 71 500 <\/span><\/span>"}]}],"id_ques":448},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00fang hay sai","title_trans":"","temp":"true_false","correct":[["f","t","f","f"]],"list":[{"point":10,"image":"","col_name":["","\u0110\u00fang","Sai"],"arr_ques":[" L\u00e0m tr\u00f2n s\u1ed1 4652 \u0111\u1ebfn h\u00e0ng ngh\u00ecn ta \u0111\u01b0\u1ee3c 4000. "," L\u00e0m tr\u00f2n s\u1ed1 6452 \u0111\u1ebfn h\u00e0ng ch\u1ee5c ta \u0111\u01b0\u1ee3c 6450. "," L\u00e0m tr\u00f2n s\u1ed1 7068,524 \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 hai ta \u0111\u01b0\u1ee3c 7068,53."," L\u00e0m tr\u00f2n s\u1ed1 7068,524 \u0111\u1ebfn \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 nh\u1ea5t ta \u0111\u01b0\u1ee3c 7068,6."],"hint":" Xem l\u1ea1i quy \u01b0\u1edbc l\u00e0m tr\u00f2n s\u1ed1.","explain":[" V\u00ec 4652 c\u00f3 ch\u1eef s\u1ed1 h\u00e0ng ngh\u00ecn l\u00e0 4 v\u00e0 ch\u1eef s\u1ed1 \u0111\u1ea7u ti\u00ean b\u1ecb b\u1ecf \u0111i l\u00e0 s\u1ed1 6 (l\u1edbn h\u01a1n 5) n\u00ean ta l\u00e0m tr\u00f2n s\u1ed1 4652 \u0111\u1ebfn ch\u1eef s\u1ed1 h\u00e0ng ngh\u00ecn ta \u0111\u01b0\u1ee3c s\u1ed1 5000","<br\/>V\u00ec 6452 c\u00f3 ch\u1eef s\u1ed1 h\u00e0ng ch\u1ee5c l\u00e0 5 v\u00e0 ch\u1eef s\u1ed1 \u0111\u1ea7u ti\u00ean b\u1ecb b\u1ecf \u0111i l\u00e0 s\u1ed1 2 (nh\u1ecf h\u01a1n 5) n\u00ean ta l\u00e0m tr\u00f2n s\u1ed1 6452 \u0111\u1ebfn ch\u1eef s\u1ed1 h\u00e0ng ch\u1ee5c ta \u0111\u01b0\u1ee3c s\u1ed1 6450 ","<br\/>V\u00ec 7068,524 c\u00f3 ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 hai l\u00e0 2 v\u00e0 ch\u1eef s\u1ed1 \u0111\u1ea7u ti\u00ean b\u1ecb b\u1ecf \u0111i l\u00e0 s\u1ed1 4 (nh\u1ecf h\u01a1n 5) n\u00ean ta l\u00e0m tr\u00f2n s\u1ed1 7068,524 \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 hai ta \u0111\u01b0\u1ee3c s\u1ed1 7068,520 ","<br\/>V\u00ec 7068,524 c\u00f3 ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 nh\u1ea5t l\u00e0 5 v\u00e0 ch\u1eef s\u1ed1 \u0111\u1ea7u ti\u00ean b\u1ecb b\u1ecf \u0111i l\u00e0 s\u1ed1 2 (nh\u1ecf h\u01a1n 5) n\u00ean ta l\u00e0m tr\u00f2n s\u1ed1 7068,524 \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 nh\u1ea5t ta \u0111\u01b0\u1ee3c s\u1ed1 7068,5"]}]}],"id_ques":449},{"time":24,"part":[{"time":24,"title":"N\u1ed1i t\u1eeb ho\u1eb7c c\u1ee5m t\u1eeb \u1edf c\u1ed9t b\u00ean tr\u00e1i v\u1edbi c\u1ed9t b\u00ean ph\u1ea3i \u0111\u1ec3 \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 \u0111\u00fang","title_trans":"","audio":"","temp":"matching","correct":[["4","1","2","3"]],"list":[{"point":10,"image":"","left":["L\u00e0m tr\u00f2n s\u1ed1 1,549 \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 nh\u1ea5t ta \u0111\u01b0\u1ee3c s\u1ed1 ","L\u00e0m tr\u00f2n s\u1ed1 1,549 \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 hai ta \u0111\u01b0\u1ee3c s\u1ed1","L\u00e0m tr\u00f2n s\u1ed1 1,5449 \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 hai ta \u0111\u01b0\u1ee3c s\u1ed1","L\u00e0m tr\u00f2n s\u1ed1 1,5449 \u0111\u1ebfn ch\u1eef s\u1ed1 th\u1eadp ph\u00e2n th\u1ee9 ba ta \u0111\u01b0\u1ee3c s\u1ed1"],"right":["1,55","1,54","1,545","1,5"],"top":100,"hint":"Xem l\u1ea1i quy \u01b0\u1edbc l\u00e0m tr\u00f2n s\u1ed1.","explain":" <b> Quy \u01b0\u1edbc l\u00e0m tr\u00f2n s\u1ed1 <\/b> <br\/> * N\u1ebfu ch\u1eef s\u1ed1 \u0111\u1ea7u ti\u00ean trong c\u00e1c ch\u1eef s\u1ed1 b\u1ecb b\u1ecf \u0111i nh\u1ecf h\u01a1n 5 th\u00ec ta gi\u1eef nguy\u00ean b\u1ed9 ph\u1eadn c\u00f2n l\u1ea1i. Trong tr\u01b0\u1eddng h\u1ee3p s\u1ed1 nguy\u00ean th\u00ec ta thay c\u00e1c ch\u1eef s\u1ed1 b\u1ecf \u0111i b\u1eb1ng c\u00e1c ch\u1eef s\u1ed1 0. <br\/> * N\u1ebfu ch\u1eef s\u1ed1 \u0111\u1ea7u ti\u00ean trong c\u00e1c ch\u1eef s\u1ed1 b\u1ecb b\u1ecf \u0111i l\u1edbn h\u01a1n ho\u1eb7c b\u1eb1ng 5 th\u00ec c\u1ed9ng th\u00eam 1 v\u00e0o ch\u1eef s\u1ed1 cu\u1ed1i c\u00f9ng c\u1ee7a b\u1ed9 ph\u1eadn c\u00f2n l\u1ea1i. Trong tr\u01b0\u1eddng h\u1ee3p s\u1ed1 nguy\u00ean th\u00ec ta thay c\u00e1c ch\u1eef s\u1ed1 b\u1ecf \u0111i b\u1eb1ng c\u00e1c ch\u1eef s\u1ed1 0."}]}],"id_ques":450}],"lesson":{"save":0,"level":3}}