{"common":{"save":0,"post_id":"6531","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"5700","post_id":"6531","mon_id":"1158921","chapter_id":"1158927","question":"<p>Tính giá tr\u1ecb c\u1ee7a \u0111a th\u1ee9c <span class=\"math-tex\">$z^2-xy+3z^2-x^2-y^2+3xy-xyz$<\/span> t\u1ea1i x = 1, y = –1, z = 2.<\/p>","options":["<strong>A. <\/strong>14","<strong>B. <\/strong>18","<strong>C. <\/strong>16","<strong>D. <\/strong>20"],"correct":"1","level":"3","hint":"","answer":"<p>Thu g\u1ecdn \u0111a th\u1ee9c<\/p><p><span class=\"math-tex\">$z^2-xy+3z^2-x^2-y^2+3xy-xyz$<\/span><\/p><p>= <span class=\"math-tex\">$4z^2+2xy-x^2-y^2-xyz$<\/span><\/p><p>T\u1ea1i x = 1, y = –1, z = 2 ta \u0111\u01b0\u1ee3c <span class=\"math-tex\">$4.2^2+2.1.(-1)-1^2-(-1)^2-1.(-1).2=14$<\/span>.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A. <\/strong>14<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-06-28 12:15:54","option_type":"txt","len":0},{"id":"5702","post_id":"6531","mon_id":"1158921","chapter_id":"1158927","question":"<p>\u0110a th\u1ee9c nào có giá tr\u1ecb là 0 t\u1ea1i x = 1, y = 1?<\/p>","options":["<strong>A. <span class=\"math-tex\">$x^2+y^2$<\/span><\/strong>","<strong>B. <span class=\"math-tex\">$2x^3-3xy$<\/span><\/strong>","<strong>C. <span class=\"math-tex\">$x^3-2y^2$<\/span><\/strong>","<strong>D. <span class=\"math-tex\">$3x^5-3y$<\/span><\/strong>"],"correct":"4","level":"3","hint":"","answer":"<p>T\u1ea1i x = 1, y = 1 thì <\/p><p>+ \u0111a th\u1ee9c A có giá tr\u1ecb là 2.<\/p><p>+ \u0111a th\u1ee9c B có giá tr\u1ecb là –1.<\/p><p>+ \u0111a th\u1ee9c C có giá tr\u1ecb là –1.<\/p><p>+ \u0111a th\u1ee9c D có giá tr\u1ecb là 0.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>D. <span class=\"math-tex\">$3x^5-3y$<\/span><\/strong><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-06-28 12:19:55","option_type":"math","len":0},{"id":"5704","post_id":"6531","mon_id":"1158921","chapter_id":"1158927","question":"<p>\u0110a th\u1ee9c nào có giá tr\u1ecb là 1 t\u1ea1i x = 1, y = 1?<\/p>","options":["<strong>A. <span class=\"math-tex\">$1-x^2$<\/span><\/strong>","<strong>B. <\/strong><span class=\"math-tex\">$xy-2x^2+2$<\/span>","<strong>C. <span class=\"math-tex\">$-5x^2+4y^2$<\/span><\/strong>","<strong>D. <span class=\"math-tex\">$-x-y$<\/span><\/strong>"],"correct":"2","level":"3","hint":"","answer":"<p>T\u1ea1i x = 1, y = 1 thì <\/p><p>+ \u0111a th\u1ee9c A có giá tr\u1ecb là 0.<\/p><p>+ \u0111a th\u1ee9c B có giá tr\u1ecb là 1.<\/p><p>+ \u0111a th\u1ee9c C có giá tr\u1ecb là –1.<\/p><p>+ \u0111a th\u1ee9c D có giá tr\u1ecb là –2.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B. <\/strong><span class=\"math-tex\">$xy-2x^2+2$<\/span><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-06-28 12:24:17","option_type":"math","len":0}]}
