{"segment":[{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["330"," 330","+330","+ 330"," 330 "]]],"list":[{"point":10,"width":60,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/bai23/lv3/img\/2.jpg' \/><\/center>124 - (135 - 341) = _input_","hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Bi\u1ec3u th\u1ee9c c\u00f3 ch\u1ee9a d\u1ea5u ngo\u1eb7c () n\u00ean ta th\u1ef1c hi\u1ec7n t\u00ednh trong ngo\u1eb7c tr\u01b0\u1edbc<br\/><b>L\u01b0u \u00fd:<\/b><br\/>Mu\u1ed1n tr\u1eeb s\u1ed1 nguy\u00ean a cho s\u1ed1 nguy\u00ean b, ta c\u1ed9ng a v\u1edbi s\u1ed1 \u0111\u1ed1i c\u1ee7a b<br\/><b>a - b = a + (-b)<\/b><\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\begin{align*}124 - (135 - 341)&= 124 -[135 + (-341)]\\\\&= 124 - [-(341 - 135)]\\\\&= 124 - (-206)\\\\&= 124 + 206\\\\&= 330\\end{align*}$<br\/>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: <span class='basic_pink'> 330<\/span><\/span> <br\/> "}]}],"id_ques":1131},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-136"," -136","- 136","-136 "," -136 "]]],"list":[{"point":10,"width":60,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/bai23/lv3/img\/2.jpg' \/><\/center>-330 - (285 - 479) = _input_","hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Bi\u1ec3u th\u1ee9c c\u00f3 ch\u1ee9a d\u1ea5u ngo\u1eb7c () n\u00ean ta th\u1ef1c hi\u1ec7n t\u00ednh trong ngo\u1eb7c tr\u01b0\u1edbc<br\/><b>L\u01b0u \u00fd:<\/b><br\/>Mu\u1ed1n tr\u1eeb s\u1ed1 nguy\u00ean a cho s\u1ed1 nguy\u00ean b, ta c\u1ed9ng a v\u1edbi s\u1ed1 \u0111\u1ed1i c\u1ee7a b<br\/><b>a - b = a + (-b)<\/b><\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\begin{align*}-330 - (285 - 479)&= -330 -[285 + (-479)]\\\\&= -330 - [-(479 - 285)]\\\\&= -330 - (-194)\\\\&= (-330) + 194\\\\&= - (330 - 194)\\\\&= -136\\end{align*}$<br\/>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: <span class='basic_pink'> -136<\/span><\/span> <br\/> "}]}],"id_ques":1132},{"time":14,"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:<br\/> |x - 5| = 3 ","select":["A. x = 8","B. x = 2","C. x = 3","D. C\u1ea3 A v\u00e0 B \u0111\u1ec1u \u0111\u00fang"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Kho\u1ea3ng c\u00e1ch t\u1eeb \u0111i\u1ec3m a \u0111\u1ebfn \u0111i\u1ec3m 0 tr\u00ean tr\u1ee5c s\u1ed1 l\u00e0 gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a s\u1ed1 nguy\u00ean a.<br\/><b> L\u01b0u \u00fd: <\/b> <b><i> x \u1edf v\u1ecb tr\u00ed l\u00e0 s\u1ed1 b\u1ecb tr\u1eeb, mu\u1ed1n t\u00ecm s\u1ed1 b\u1ecb tr\u1eeb ta l\u1ea5y hi\u1ec7u c\u1ed9ng v\u1edbi s\u1ed1 tr\u1eeb<\/i><\/b><\/span> <br\/><br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>|x - 5| = 3 <br\/>$\\Rightarrow $ x - 5 = 3 ho\u1eb7c x - 5 = -3<br\/>TH1: <br\/> $\\begin{align*}x - 5&= 3\\\\x&= 3 + 5\\\\x&= 8\\end{align*}$<br\/>TH2:<br\/> $\\begin{align*}x - 5&= -3\\\\x&= -3 + 5\\\\x&= 2\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> D. C\u1ea3 A v\u00e0 B \u0111\u1ec1u \u0111\u00fang<\/span><br\/><span class='basic_green'>Nh\u1eadn x\u00e9t:<\/span> |a| = a ho\u1eb7c = -a<br\/>+ |a| = a n\u1ebfu a > 0 (V\u00ed d\u1ee5 |2| = 2) <br\/>+ |a| = -a n\u1ebfu a < 0 (V\u00ed d\u1ee5: |-2| = -(-2) = 2)<\/span> <br\/><\/span>","column":2}]}],"id_ques":1133},{"time":14,"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 x, bi\u1ebft:<br\/>x - 12 = (-9) - 18 ","select":["A. x = -15","B. x = 15","C. x = 39","D. x = -39"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: T\u00ednh v\u1ebf ph\u1ea3i<br\/>B\u01b0\u1edbc 2: T\u00ecm x<br\/><b> L\u01b0u \u00fd: <\/b> <b><i> x \u1edf v\u1ecb tr\u00ed l\u00e0 s\u1ed1 b\u1ecb tr\u1eeb, mu\u1ed1n t\u00ecm s\u1ed1 b\u1ecb tr\u1eeb ta l\u1ea5y hi\u1ec7u c\u1ed9ng v\u1edbi s\u1ed1 tr\u1eeb<\/i><\/b><\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\begin{align*}x - 12 &= (-9) - 18\\\\x -12&= (-9) + (-18) \\\\x - 12&= -(9 + 18)\\\\x - 12&= -27\\\\x&= -27 + 12\\\\x&= - (27 - 12)\\\\x&= -15\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> A. x = -15<\/span><\/span> <br\/>","column":2}]}],"id_ques":1134},{"time":14,"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: <br\/>A = 358 - 472 + m - n v\u1edbi m = 126; n = -202","select":["A = 214","A = -214","A = 442","A = -442"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>B\u01b0\u1edbc 1: Thay gi\u00e1 tr\u1ecb c\u1ee7a m, n v\u00e0o bi\u1ec3u th\u1ee9c<br\/>B\u01b0\u1edbc 2: T\u00ednh gi\u00e1 tr\u1ecb bi\u1ec3u th\u1ee9c<br\/><b>L\u01b0u \u00fd: <\/b> <b><i>Bi\u1ec3u th\u1ee9c ch\u1ec9 ch\u1ee9a ph\u00e9p t\u00ednh c\u1ed9ng v\u00e0 ph\u00e9p t\u00ednh tr\u1eeb n\u00ean ta th\u1ef1c hi\u1ec7n t\u00ednh l\u1ea7n l\u01b0\u1ee3t t\u1eeb tr\u00e1i qua ph\u1ea3i.<\/i><\/b><\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Thay m = 126; n = -202 v\u00e0o bi\u1ec3u th\u1ee9c ta \u0111\u01b0\u1ee3c:<br\/>$\\begin{align*}A&= 358 - 472 + 126 - (-202)\\\\A&= 358 + (-472) + 126 + 202 \\\\A&= -114 + 126 + 202\\\\ A&= 12 + 202\\\\A&= 214\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>A = 214<\/span><\/span> <br\/>","column":2}]}],"id_ques":1135},{"time":14,"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\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c: <br\/>A = -1125 + 247 - (-m) + n v\u1edbi m = 211; n = -325","select":["A = 352","A = -352","A = 992","A = -992"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>B\u01b0\u1edbc 1: Thay gi\u00e1 tr\u1ecb c\u1ee7a m, n v\u00e0o bi\u1ec3u th\u1ee9c<br\/>B\u01b0\u1edbc 2: T\u00ednh gi\u00e1 tr\u1ecb bi\u1ec3u th\u1ee9c<br\/><b>L\u01b0u \u00fd: <\/b> <b><i>Bi\u1ec3u th\u1ee9c ch\u1ec9 ch\u1ee9a ph\u00e9p t\u00ednh c\u1ed9ng v\u00e0 ph\u00e9p t\u00ednh tr\u1eeb n\u00ean ta th\u1ef1c hi\u1ec7n t\u00ednh l\u1ea7n l\u01b0\u1ee3t t\u1eeb tr\u00e1i qua ph\u1ea3i.<\/i><\/b><\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> Thay m = 211; n = -325 v\u00e0o bi\u1ec3u th\u1ee9c ta \u0111\u01b0\u1ee3c:<br\/>$\\begin{align*}A&= -1125 + 247 - (-211) + (-325)\\\\A&= -1125 + 247 + 211 + (-325) \\\\A&= -878 + 211 + (-325)\\\\ A&= -667 + (-325)\\\\A&= -992\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>A = -992<\/span><\/span> <br\/>","column":2}]}],"id_ques":1136},{"time":14,"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 x, bi\u1ebft: x + 5 l\u00e0 s\u1ed1 nguy\u00ean d\u01b0\u01a1ng nh\u1ecf nh\u1ea5t.","select":["A. x = -4","B. x = 4","C. x = -5","D. x = 5"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: T\u00ecm s\u1ed1 nguy\u00ean d\u01b0\u01a1ng nh\u1ecf nh\u1ea5t<br\/>B\u01b0\u1edbc 2: T\u00ecm x<\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> S\u1ed1 nguy\u00ean d\u01b0\u01a1ng nh\u1ecf nh\u1ea5t l\u00e0: 1, n\u00ean x + 5 = 1<br\/>$\\begin{align*}x + 5 &= 1\\\\x &= 1 - 5 \\\\x &= 1 + (-5)\\\\x &= -4\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> A. x = -4<\/span><\/span> <br\/>","column":2}]}],"id_ques":1137},{"time":14,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":10,"ques":" Hi\u1ec7u c\u1ee7a s\u1ed1 li\u1ec1n tr\u01b0\u1edbc v\u00e0 s\u1ed1 li\u1ec1n sau c\u1ee7a s\u1ed1 -35 b\u1eb1ng <span class='basic_hoi_black'>?<\/span>","select":["A. 2","B. -2","C. 70","D. -70"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: T\u00ecm s\u1ed1 li\u1ec1n tr\u01b0\u1edbc v\u00e0 s\u1ed1 li\u1ec1n sau c\u1ee7a s\u1ed1 -35<br\/>B\u01b0\u1edbc 2: T\u00ednh hi\u1ec7u<\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> <br\/>S\u1ed1 li\u1ec1n tr\u01b0\u1edbc c\u1ee7a s\u1ed1 -35 l\u00e0: -36<br\/>S\u1ed1 li\u1ec1n sau c\u1ee7a s\u1ed1 -35 l\u00e0: -34<br\/> Hi\u1ec7u c\u1ee7a hai s\u1ed1 tr\u00ean l\u00e0:<br\/>$\\begin{align*} -36 - (-34)&= -36 + 34 \\\\ &= -2\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> B. -2<\/span><\/span> <br\/>","column":2}]}],"id_ques":1138},{"time":14,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":" (a -2) v\u00e0 (2 -a) l\u00e0 hai s\u1ed1 \u0111\u1ed1i nhau. \u0110\u00fang hay sai?","select":["A. \u0110\u00fang","B. Sai"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> Hai s\u1ed1 \u0111\u1ed1i nhau c\u00f3 t\u1ed5ng b\u1eb1ng 0.<\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span> Ta c\u00f3:<br\/>$\\begin{align*} (a - 2) + (2 - a)&= a - 2 + 2 - a \\\\ &= (a - a) + [(-2) + 2]\\\\&= 0 + 0\\\\&= 0\\end{align*}$<br\/> N\u00ean a - 2 v\u00e0 2 - a l\u00e0 hai s\u1ed1 \u0111\u1ed1i nhau<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> A. \u0110\u00fang<\/span><\/span> <br\/>","column":2}]}],"id_ques":1139},{"time":14,"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 nhanh: <br\/>A = -1 - 2 - 3 - 4 - ... - 98","select":["A = -2450","A = -2451","A = -4851","A = -4850"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>B\u01b0\u1edbc 1: Chuy\u1ec3n ph\u00e9p t\u00ednh tr\u1eeb v\u1ec1 d\u1ea1ng ph\u00e9p t\u00ednh c\u1ed9ng<br\/>B\u01b0\u1edbc 2: Nh\u00f3m c\u00e1c c\u1eb7p c\u00f3 t\u1ed5ng l\u00e0 s\u1ed1 tr\u00f2n ch\u1ee5c, tr\u00f2n tr\u0103m,... \u0111\u1ec3 th\u1ef1c hi\u1ec7n t\u00ednh nhanh.<br\/><b>L\u01b0u \u00fd: <\/b> <b><i> Mu\u1ed1n tr\u1eeb s\u1ed1 nguy\u00ean a cho s\u1ed1 nguy\u00ean b, ta c\u1ed9ng a v\u1edbi s\u1ed1 \u0111\u1ed1i c\u1ee7a b<\/i><\/b><\/span> <br\/><br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> $\\begin{align*}A&= -1 - 2 - 3 - 4 - ... - 98\\\\A&= -1 + (-2) + (-3) + (-4) + ... + (-98) \\\\A&= (-1) + [(-2) + (-98)] + [(-3) + (-97)] + [(-4) + (-96)] + ... + (-50)\\\\ A&= (-1) + (-100) + (-100) + (-100) + + ... + (-50) \\\\A&= -(100 + 100 + 100 + ...) - (50 + 1)\\\\A&= -(100 . 48) - (51)\\\\A&= -4800 + (-51)\\\\A&= -4851\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'>A = -4851<\/span><\/span> <br\/><\/span><span class='basic_left'><span class='basic_green'>L\u01b0u \u00fd: <\/span><br\/>S\u1ed1 s\u1ed1 h\u1ea1ng c\u1ee7a m\u1ed9t d\u00e3y s\u1ed1 c\u00e1ch \u0111\u1ec1u \u0111\u01b0\u1ee3c t\u00ednh theo c\u00f4ng th\u1ee9c: ( s\u1ed1 cu\u1ed1i - s\u1ed1 \u0111\u1ea7u) : kho\u1ea3ng c\u00e1ch + 1<br\/>Do \u0111\u00f3 s\u1ed1 s\u1ed1 h\u1ea1ng c\u1ee7a d\u00e3y s\u1ed1 li\u00ean ti\u1ebfp t\u1eeb 1 \u0111\u1ebfn 98 c\u00f3: $ \\dfrac{98 - 1}{1} + 1 = 98$ (s\u1ed1)<br\/>Suy ra d\u00e3y s\u1ed1 li\u00ean ti\u1ebfp t\u1eeb 1 \u0111\u1ebfn 98 tr\u1eeb s\u1ed1 50 v\u00e0 s\u1ed1 1 ra ta \u0111\u01b0\u1ee3c s\u1ed1 c\u1eb7p l\u00e0: $\\dfrac{98 - 2}{2}= 48$ (c\u1eb7p)<br\/>$\\Rightarrow$ d\u00f2ng th\u1ee9 5 c\u1ee7a b\u00e0i gi\u1ea3i ta c\u00f3 48 s\u1ed1 100<\/span>","column":2}]}],"id_ques":1140}],"lesson":{"save":0,"level":3}}