{"common":{"save":0,"post_id":"7381","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7031","post_id":"7381","mon_id":"1159278","chapter_id":"1159281","question":"<p>Giá tr\u1ecb nào c\u1ee7a m d\u01b0\u1edbi \u0111ây \u0111\u1ec3 \u0111i\u1ec3m <span style=\"color:#2980b9;\"><strong>M(2; 1)<\/strong><\/span> thu\u1ed9c \u0111\u1ed3 th\u1ecb (D) c\u1ee7a ph\u01b0\u01a1ng trình <span style=\"color:#c0392b;\"><strong>mx – 3y = 5<\/strong><\/span>?<\/p>","options":["<strong>A.<\/strong> –3","<strong>B.<\/strong> 3","<strong>C.<\/strong> 4","<strong>D.<\/strong> –5"],"correct":"3","level":"3","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> 4<\/span><\/p><p>Thay x = 2, y = 1 vào ph\u01b0\u01a1ng trình ta \u0111\u01b0\u1ee3c 2m – 3 = 5 suy ra m = 4.<\/p>","type":"choose","extra_type":"shape1","time":"0","user_id":"127","test":"0","date":"2024-10-01 02:10:04","option_type":"txt","len":0},{"id":"7033","post_id":"7381","mon_id":"1159278","chapter_id":"1159281","question":"<p>Cho hai ph\u01b0\u01a1ng trình: <span class=\"math-tex\">$x-2y=-10$<\/span> và <span class=\"math-tex\">$x+y=-1$<\/span>. Nghi\u1ec7m chung c\u1ee7a hai ph\u01b0\u01a1ng trình là<\/p>","options":["<strong>A.<\/strong> (–2; 5)","<strong>B.<\/strong> (–8; 4)","<strong>C.<\/strong> (7; –3)","<strong>D.<\/strong> (–4; 3)"],"correct":"4","level":"3","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>D.<\/strong> (–4; 3)<\/span><\/p><p>Ta có: <span class=\"math-tex\">$-4-2.3=-10$<\/span> nên <span style=\"color:#16a085;\">(–4; 3) <\/span>là nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng trình <span class=\"math-tex\">$x-2y=-10$<\/span>.<\/p><p>Ta có: <span class=\"math-tex\">$-4+3=-1$<\/span> nên <span style=\"color:#16a085;\">(–4; 3) <\/span>là nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng trình <span class=\"math-tex\">$x+y=-1$<\/span>.<\/p><p>V\u1eady <span style=\"color:#16a085;\">(–4; 3)<\/span> là nghi\u1ec7m chung c\u1ee7a hai ph\u01b0\u01a1ng trình trên.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-01 02:18:38","option_type":"txt","len":2},{"id":"7034","post_id":"7381","mon_id":"1159278","chapter_id":"1159281","question":"<p>Tìm a và b \u0111\u1ec3 (–2; 3) là nghi\u1ec7m c\u1ee7a h\u1ec7 ph\u01b0\u01a1ng trình <span class=\"math-tex\">$\\begin{cases}ax+y=5\\\\3x+by=0\\end{cases}$<\/span>.<\/p>","options":["<strong>A.<\/strong> (a; b) = (–2; 1)","<strong>B.<\/strong> (a; b) = (–1; 2)","<strong>C.<\/strong> (a; b) = (–3; 3)","<strong>D.<\/strong> (a; b) = (2; –4)"],"correct":"2","level":"3","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> (a; b) = (–1; 2)<\/span><\/p><p>Thay x = –2, y = 3 ta có: <span class=\"math-tex\">$\\begin{cases}-2a+3=5\\\\3.(-2)+3b=0\\end{cases}$<\/span> suy ra <span class=\"math-tex\">$\\begin{cases}a=-1\\\\b=2\\end{cases}$<\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-01 02:19:30","option_type":"txt","len":2}]}
