{"common":{"save":0,"post_id":"6477","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7087","mon_id":"1158767","chapter_id":"1158892","post_id":"6477","question":"<p>Hai \u0111\u01b0\u1eddng th\u1eb3ng a: mx + 2y = 0 và b: 2x + my = 9m – 1 c\u1eaft nhau và ch\u1ec9 khi<\/p>","options":["<strong>A.<\/strong> m <span class=\"math-tex\">$\\ne$<\/span> 2","<strong>B.<\/strong> m<span class=\"math-tex\">$\\ne$<\/span> –2","<strong>C.<\/strong> m <span class=\"math-tex\">$\\ne \\pm$<\/span> 2","<strong>D.<\/strong> m <span class=\"math-tex\">$\\ne$<\/span> 4"],"correct":"3","level":"1","hint":"","answer":"<p>a có m\u1ed9t vect\u01a1 pháp tuy\u1ebfn là <span class=\"math-tex\">$\\overrightarrow{u}$<\/span> = (m; 2).<\/p><p>b có m\u1ed9t vect\u01a1 pháp tuy\u1ebfn là <span class=\"math-tex\">$\\overrightarrow{v}$<\/span> = (2; m).<\/p><p>a và b c\u1eaft nhau ⇔ <span class=\"math-tex\">$\\overrightarrow{u}$<\/span> và <span class=\"math-tex\">$\\overrightarrow{v}$<\/span> không cùng ph\u01b0\u01a1ng ⇔ m.m <span class=\"math-tex\">$\\ne$<\/span> 2.2 ⇔ m <span class=\"math-tex\">$\\ne$<\/span> <span class=\"math-tex\">$\\pm$<\/span>2.<\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"><strong>C.<\/strong> m <span class=\"math-tex\">$\\ne \\pm$<\/span> 2.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-06-02 07:59:10","option_type":"math","len":0},{"id":"7090","mon_id":"1158767","chapter_id":"1158892","post_id":"6477","question":"<p>V\u1edbi giá tr\u1ecb nào c\u1ee7a m thì hai \u0111\u01b0\u1eddng th\u1eb3ng <\/p><p>a: 4x + 9y + 5 = 0 và b: 2(m – 1)x + m²y + 5 = 0 trùng nhau?<\/p>","options":["<strong>A.<\/strong> m = 2","<strong>B.<\/strong> m = 3","<strong>C.<\/strong> m = <span class=\"math-tex\">$\\pm$<\/span> 3","<strong>D.<\/strong> m = <span class=\"math-tex\">$\\pm$<\/span> 2"],"correct":"2","level":"1","hint":"","answer":"<p>\u0110\u1ec3 a và b trùng nhau thì<\/p><p><span class=\"math-tex\">$\\dfrac{2(m-1)}{4}=\\dfrac{m^2}{9}=\\dfrac{5}{5}$<\/span> = 1 ⇔ <span class=\"math-tex\">$\\begin{cases}2(m-1)=4\\\\m^2=9\\end{cases}$<\/span> ⇔ <span class=\"math-tex\">$\\begin{cases}m=3\\\\m=\\pm3\\end{cases}$<\/span> ⇔ m = 3.<\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"> <strong>B.<\/strong> m = 3.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-06-02 08:05:24","option_type":"math","len":0},{"id":"7092","mon_id":"1158767","chapter_id":"1158892","post_id":"6477","question":"<p>Tìm m \u0111\u1ec3 hai \u0111\u01b0\u1eddng th\u1eb3ng a: x – 3y + 4 = 0 và b: <span class=\"math-tex\">$\\begin{cases}x=2-4t\\\\y=1-3mt\\end{cases}$<\/span> c\u1eaft nhau.<\/p>","options":["<strong>A.<\/strong> m <span class=\"math-tex\">$\\ne-\\dfrac{4}{9}$<\/span>","<strong>B.<\/strong> m <span class=\"math-tex\">$\\ne$<\/span> 4","<strong>C.<\/strong> m <span class=\"math-tex\">$\\ne$<\/span> <span class=\"math-tex\">$\\dfrac{4}{9}$<\/span>","<strong>D.<\/strong> m = <span class=\"math-tex\">$\\dfrac{4}{9}$<\/span>"],"correct":"3","level":"1","hint":"","answer":"<p>a có m\u1ed9t vect\u01a1 pháp tuy\u1ebfn là <span class=\"math-tex\">$\\overrightarrow{u}$<\/span> = (1; –3).<\/p><p>b có m\u1ed9t vect\u01a1 ch\u1ec9 ph\u01b0\u01a1ng là <span class=\"math-tex\">$\\overrightarrow{v_1}$<\/span> = (–4; –3m) nên có m\u1ed9t vect\u01a1 pháp tuy\u1ebfn là <span class=\"math-tex\">$\\overrightarrow{v_2}$<\/span> = (3m; –4).<\/p><p>\u0110\u1ec3 a và b c\u1eaft nhau thì <span class=\"math-tex\">$\\dfrac{3m}{1}\\ne\\dfrac{-4}{-3}$<\/span> ⇔ –9m <span class=\"math-tex\">$\\ne$<\/span> –4 ⇔ m <span class=\"math-tex\">$m\\ne\\dfrac{4}{9}$<\/span>.<\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"> <strong>C.<\/strong> m <span class=\"math-tex\">$\\ne$<\/span> <span class=\"math-tex\">$\\dfrac{4}{9}$<\/span>.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-06-02 08:12:01","option_type":"math","len":0}]}