Phép cộng và phép trừ đa thức một biến

Home Toán lớp 7 - tập 2 Chương 7: Biểu thức đại số và đa thức một biến Bài 26: Phép cộng và phép trừ đa thức một biếnBài tập nâng cao

{"common":{"save":0,"post_id":"5811","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8538","post_id":"5811","mon_id":"1158532","chapter_id":"1158660","question":"Vi\u1ebft \u0111a th\u1ee9c bi\u1ec3u di\u1ec5n ph\u1ea7n di\u1ec7n tích S màu xanh phía trong khung trang \u1edf hình d\u01b0\u1edbi<\/p><svg height=\"170\" width=\"260\"> <g><title><\/title><rect fill=\"#fff\" height=\"172\" id=\"canvas_background\" width=\"262\" x=\"-1\" y=\"-1\"><\/rect> <g display=\"none\" id=\"canvasGrid\"> <rect fill=\"url(#gridpattern)\" height=\"100%\" id=\"svg_2\" stroke-width=\"0\" width=\"100%\" x=\"0\" y=\"0\"><\/rect> <\/g> <\/g> <g><title><\/title><g id=\"svg_18\"> <g id=\"svg_19\"> <rect fill=\"#fff\" height=\"99\" id=\"svg_1\" stroke=\"#000\" stroke-width=\"1.5\" width=\"178\" x=\"25\" y=\"22.25\"><\/rect> <path d=\"m25.6,50.71713l51.84183,-28.70338l73.31634,0l51.84183,28.70338l0,40.59322l-51.84183,28.70338l-73.31634,0l-51.84183,-28.70338l0,-40.59322z\" fill=\"#aaffd4\" id=\"svg_3\" stroke=\"#000\" stroke-width=\"1.5\"><\/path> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"24\" id=\"svg_5\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"104\" xml:space=\"preserve\" y=\"80.25\">S<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"15\" id=\"svg_6\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"45\" xml:space=\"preserve\" y=\"15.25\">2x<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"15\" id=\"svg_7\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"176\" xml:space=\"preserve\" y=\"13.25\">2x<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"15\" id=\"svg_8\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"12\" xml:space=\"preserve\" y=\"41.25\">x<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"15\" id=\"svg_9\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"208\" xml:space=\"preserve\" y=\"40.25\">x<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"15\" id=\"svg_10\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"11\" xml:space=\"preserve\" y=\"110.25\">x<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"15\" id=\"svg_11\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"40\" xml:space=\"preserve\" y=\"135.25\">2x<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"15\" id=\"svg_12\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"177\" xml:space=\"preserve\" y=\"137.25\">2x<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"15\" id=\"svg_14\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"206\" xml:space=\"preserve\" y=\"111.25\">x<\/text> <path d=\"m229.75885,38.23508c0,-8.61928 -1.48672,-13.93253 -7.00884,-14.99518l0.14159,-0.23614c7.99999,0.23614 10.19468,4.2506 10.19468,17.12048l0,17.82892c0,7.91084 0.49557,11.68916 5.66371,13.81446l0,0.23614c-5.09734,2.1253 -5.66371,5.90361 -5.66371,13.69639l0,19.00964c0,12.39759 -2.76106,15.93976 -10.19468,16.29398l-0.14159,-0.23555c5.66371,-1.41687 7.00884,-6.13976 7.00884,-15.11384l0,-19.00964c0,-8.02892 0.63717,-12.63374 5.9469,-14.64096l0,-0.23614c-5.38053,-2.1253 -5.9469,-7.08434 -5.9469,-15.11325l0,-18.41928z\" fill=\"#fff\" id=\"svg_13\" stroke=\"#000\" stroke-width=\"1.5\"><\/path> <path d=\"m115.06361,82.3834c0,-15.56747 -1.02212,-25.16386 -4.81858,-27.08313l0.09735,-0.42651c5.5,0.42651 7.00885,7.67711 7.00885,30.92169l0,32.20121c0,14.28795 0.34071,21.11205 3.89381,24.9506l0,0.42651c-3.50442,3.83855 -3.89381,10.66265 -3.89381,24.73735l0,34.33374c0,22.39157 -1.89823,28.78916 -7.00885,29.42892l-0.09735,-0.42544c3.89381,-2.55904 4.81858,-11.08916 4.81858,-27.29745l0,-34.33374c0,-14.50121 0.43805,-22.81807 4.0885,-26.44337l0,-0.42651c-3.69911,-3.83855 -4.0885,-12.79518 -4.0885,-27.29639l0,-33.26747z\" fill=\"#fff\" id=\"svg_15\" stroke=\"#000\" stroke-width=\"1.5\" transform=\"rotate(90 115.74502563476561,143.3737487792969) \"><\/path> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"15\" id=\"svg_16\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"245\" xml:space=\"preserve\" y=\"78.25\">6<\/text> <text fill=\"#000000\" fill-opacity=\"null\" font-family=\"Helvetica, Arial, sans-serif\" font-size=\"15\" id=\"svg_17\" stroke=\"#000\" stroke-opacity=\"null\" stroke-width=\"0\" text-anchor=\"start\" x=\"112\" xml:space=\"preserve\" y=\"167.25\">8<\/text> <\/g> <\/g> <\/g> <\/svg><\/span><\/p>","options":["A.<\/strong> S = 48 - 4x²","B. <\/strong>S = 4x²","C.<\/strong> S = 48 - 8x²","D.<\/strong> S = 8x²"],"correct":"1","level":"3","hint":"Tính di\u1ec7n tích c\u1ee7a hình ch\u1eef nh\u1eadt bên ngoài, tính di\u1ec7n tích c\u1ee7a các hình tam giác nh\u1ecf màu tr\u1eafng. S b\u1eb1ng di\u1ec7n tích hình ch\u1eef nh\u1eadt tr\u1eeb di\u1ec7n tích c\u1ee7a các tam giác nh\u1ecf.<\/p>","answer":"Di\u1ec7n tích c\u1ee7a hình ch\u1eef nh\u1eadt bên ngoài là<\/p>6 . 8 = 48<\/p>Vì các tam giác nh\u1ecf màu tr\u1eafng là các tam giác vuông có hai c\u1ea1nh góc vuông l\u1ea7n l\u01b0\u1ee3t là x và 2x nên di\u1ec7n tích c\u1ee7a m\u1ed9t tam giác nh\u1ecf màu tr\u1eafng là <\/p>$\\dfrac{1}{2}$<\/span> . x . 2x = x²<\/p>Vì b\u1ed1n tam giác nh\u1ecf b\u1eb1ng nhau nên t\u1ed5ng di\u1ec7n tích các tam giác là <\/p>4 . x² = 4x²  <\/p>Di\u1ec7n tích S màu xanh là<\/p>S = 48 - 4x²<\/p>\u0110áp án \u0111úng là   A.<\/strong> S = 48 - 4x²<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-06-01 09:20:59","option_type":"txt","len":2},{"id":"8552","post_id":"5811","mon_id":"1158532","chapter_id":"1158660","question":"Tìm \u0111a th\u1ee9c P bi\u1ebft  M + P = N và <\/p>M = $x^3 - 5x^2 + x + 2$<\/span> ; N = $5x^3 - x^2 + 8x - 3$<\/span><\/p>","options":["A.<\/strong> P = $4x^3+4x^2+7x-5$<\/span>","B.<\/strong> P = $6x^3-6x^2+9x-1$<\/span>","C. <\/strong>P = $-4x^3-4x^2-7x+5$<\/span>","D. <\/strong>P = $-6x^3+6x^2-9x+1$<\/span>"],"correct":"1","level":"3","hint":"M + P = N ⇒ P = N - M<\/p>","answer":"M + P = N ⇒ P = N - M<\/p>Do \u0111ó P = ($5x^3 - x^2 + 8x - 3$<\/span>) – ($x^3 - 5x^2 + x + 2$<\/span>)<\/p>              = $5x^3 - x^2 + 8x - 3 - x^3 + 5x^2 - x - 2$<\/span><\/p>              = $5x^3 - x^3 - x^2 + 5x^2 + 8x - x - 3 - 2$<\/span><\/p>              = $4x^3 + 4x^2 + 7x - 5$<\/span><\/p>\u0110áp án \u0111úng là   A.<\/strong> P = $4x^3+4x^2+7x-5$<\/span><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-06-01 10:12:23","option_type":"math","len":0},{"id":"8554","post_id":"5811","mon_id":"1158532","chapter_id":"1158660","question":"Bi\u1ebft M + P = N và M = $x^3 - 5x^2 + x + 2$<\/span> ; N = $5x^3 - x^2 + 8x - 3$<\/span> .<\/p>H\u1ec7 s\u1ed1 cao nh\u1ea5t c\u1ee7a \u0111a th\u1ee9c P là<\/p>","options":["4","5","0","3"],"correct":"1","level":"3","hint":"M + P = N ⇒ P = N - M<\/p>","answer":"Ta có   M + P = N <\/p>Do \u0111ó  P = N – M<\/p>               = ($5x^3 - x^2 + 8x - 3$<\/span>) – ($x^3 - 5x^2 + x + 2$<\/span>)<\/p>               = $5x^3 - x^2 + 8x - 3 - x^3 + 5x^2 - x - 2$<\/span><\/p>               = $5x^3 - x^3 - x^2 + 5x^2 + 8x - x - 3 - 2$<\/span><\/p>               = $4x^3 + 4x^2 + 7x - 5$<\/span><\/p>V\u1eady h\u1ec7 s\u1ed1 cao nh\u1ea5t c\u1ee7a P là   4<\/p>\u0110áp án \u0111úng là     4<\/strong><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-06-01 10:15:26","option_type":"number","len":0}]}