[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.29,0:00:01.32,Default,,0000,0000,0000,,Hãy cùng tìm tích của
Dialogue: 0,0:00:01.32,0:00:05.02,Default,,0000,0000,0000,,x trừ 4 và x cộng 7.
Dialogue: 0,0:00:05.02,0:00:08.42,Default,,0000,0000,0000,,Chúng ta sẽ viết tích đó duới dạng thu gọn
Dialogue: 0,0:00:08.42,0:00:10.55,Default,,0000,0000,0000,,có nghĩa là viết
Dialogue: 0,0:00:10.55,0:00:13.95,Default,,0000,0000,0000,,hệ số với số mũ bậc 2,
Dialogue: 0,0:00:13.95,0:00:16.61,Default,,0000,0000,0000,,a x bình phương cộng hệ số b
Dialogue: 0,0:00:16.61,0:00:19.52,Default,,0000,0000,0000,,với số mũ bậc 1 cộng hệ số tự do.
Dialogue: 0,0:00:19.52,0:00:22.42,Default,,0000,0000,0000,,Đây là dạng thu gọn của đa thức.
Dialogue: 0,0:00:22.42,0:00:24.95,Default,,0000,0000,0000,,Đó là dạng đa thức tích mà ta muốn viết.
Dialogue: 0,0:00:24.95,0:00:26.15,Default,,0000,0000,0000,,Mình khuyến khích bạn
Dialogue: 0,0:00:26.15,0:00:28.26,Default,,0000,0000,0000,,dừng video và tự suy nghĩ.
Dialogue: 0,0:00:28.26,0:00:30.29,Default,,0000,0000,0000,,Hãy bắt đầu giải nào.
Dialogue: 0,0:00:30.29,0:00:32.89,Default,,0000,0000,0000,,Mấu chốt khi nhân hai nhị thức như thế này,
Dialogue: 0,0:00:32.89,0:00:34.82,Default,,0000,0000,0000,,hoặc khi nhân bất kì đa thức nào
Dialogue: 0,0:00:34.82,0:00:37.42,Default,,0000,0000,0000,,là nhớ đến tính chất phân phối
Dialogue: 0,0:00:37.42,0:00:39.69,Default,,0000,0000,0000,,mà chúng ta đều biết rõ ở thời điểm này.
Dialogue: 0,0:00:39.69,0:00:41.62,Default,,0000,0000,0000,,Vậy chúng ta có thể hiểu bài toán này
Dialogue: 0,0:00:41.62,0:00:43.92,Default,,0000,0000,0000,,là nhân phân phối x trừ 4
Dialogue: 0,0:00:43.92,0:00:46.72,Default,,0000,0000,0000,,với x và 7.
Dialogue: 0,0:00:46.72,0:00:48.72,Default,,0000,0000,0000,,Ta có thể nói nó cũng chính là
Dialogue: 0,0:00:48.72,0:00:51.61,Default,,0000,0000,0000,,x trừ 4 nhân x
Dialogue: 0,0:00:51.61,0:00:55.22,Default,,0000,0000,0000,,cộng x trừ 4 nhân 7.
Dialogue: 0,0:00:55.22,0:00:56.59,Default,,0000,0000,0000,,Hãy viết nó ra.
Dialogue: 0,0:00:56.59,0:00:58.82,Default,,0000,0000,0000,,x trừ 4 nhân x có thể viết lại là
Dialogue: 0,0:00:58.82,0:01:03.82,Default,,0000,0000,0000,,x nhân x trừ 4.
Dialogue: 0,0:01:04.52,0:01:07.65,Default,,0000,0000,0000,,Đó chính là nhân phân phối:
Dialogue: 0,0:01:07.65,0:01:08.85,Default,,0000,0000,0000,,nhân x trừ 4 với x.
Dialogue: 0,0:01:08.85,0:01:13.59,Default,,0000,0000,0000,,Cộng 7 nhân x trừ 4.
Dialogue: 0,0:01:13.59,0:01:15.89,Default,,0000,0000,0000,,Nhân x trừ 4. Tất cả những gì ta làm là phân phối x trừ 4
Dialogue: 0,0:01:15.89,0:01:19.05,Default,,0000,0000,0000,,Tất cả những gì ta làm là phân phối x trừ 4
Dialogue: 0,0:01:19.05,0:01:20.99,Default,,0000,0000,0000,,Ta lấy cả cụm này và nhân nó với
Dialogue: 0,0:01:20.99,0:01:22.82,Default,,0000,0000,0000,,từng nhân tử ở kia.
Dialogue: 0,0:01:22.82,0:01:24.89,Default,,0000,0000,0000,,Ta nhân x với x trừ 4
Dialogue: 0,0:01:24.89,0:01:27.45,Default,,0000,0000,0000,,và nhân 7 với x trừ 4.
Dialogue: 0,0:01:27.45,0:01:29.95,Default,,0000,0000,0000,,Bây giờ ta có những cụm này, ta có thể
Dialogue: 0,0:01:29.95,0:01:31.88,Default,,0000,0000,0000,,gọi chúng là các nhân tử riêng biệt.
Dialogue: 0,0:01:31.88,0:01:34.61,Default,,0000,0000,0000,,Để rút gọn, hay để nhân chúng với nhau
Dialogue: 0,0:01:34.61,0:01:35.49,Default,,0000,0000,0000,,ta chỉ cần phân phối.
Dialogue: 0,0:01:35.49,0:01:37.79,Default,,0000,0000,0000,,Đầu tiên ta cần phân phối ẩn x màu xanh.
Dialogue: 0,0:01:37.79,0:01:40.05,Default,,0000,0000,0000,,Ở đây ta cần phân phối số 7 màu xanh.
Dialogue: 0,0:01:40.05,0:01:41.62,Default,,0000,0000,0000,,Hãy làm nào.
Dialogue: 0,0:01:41.62,0:01:46.62,Default,,0000,0000,0000,,X nhân x là x bình phương.
Dialogue: 0,0:01:46.72,0:01:49.72,Default,,0000,0000,0000,,X nhân một số âm ở đây,
Dialogue: 0,0:01:49.72,0:01:52.25,Default,,0000,0000,0000,,nên ta nói âm 4 sẽ thành âm 4 x.
Dialogue: 0,0:01:52.25,0:01:55.35,Default,,0000,0000,0000,,
Dialogue: 0,0:01:55.35,0:02:00.15,Default,,0000,0000,0000,,
Dialogue: 0,0:02:00.15,0:02:03.29,Default,,0000,0000,0000,,
Dialogue: 0,0:02:03.29,0:02:06.82,Default,,0000,0000,0000,,
Dialogue: 0,0:02:06.82,0:02:09.72,Default,,0000,0000,0000,,
Dialogue: 0,0:02:09.72,0:02:11.75,Default,,0000,0000,0000,,
Dialogue: 0,0:02:11.75,0:02:13.22,Default,,0000,0000,0000,,
Dialogue: 0,0:02:13.22,0:02:15.02,Default,,0000,0000,0000,,
Dialogue: 0,0:02:15.02,0:02:18.99,Default,,0000,0000,0000,,
Dialogue: 0,0:02:18.99,0:02:20.39,Default,,0000,0000,0000,,
Dialogue: 0,0:02:20.39,0:02:21.72,Default,,0000,0000,0000,,
Dialogue: 0,0:02:21.72,0:02:24.59,Default,,0000,0000,0000,,
Dialogue: 0,0:02:24.59,0:02:27.92,Default,,0000,0000,0000,,
Dialogue: 0,0:02:27.92,0:02:32.92,Default,,0000,0000,0000,,
Dialogue: 0,0:02:33.15,0:02:37.12,Default,,0000,0000,0000,,
Dialogue: 0,0:02:37.12,0:02:38.51,Default,,0000,0000,0000,,
Dialogue: 0,0:02:38.51,0:02:40.22,Default,,0000,0000,0000,,
Dialogue: 0,0:02:40.22,0:02:42.05,Default,,0000,0000,0000,,
Dialogue: 0,0:02:42.05,0:02:43.22,Default,,0000,0000,0000,,
Dialogue: 0,0:02:43.22,0:02:46.19,Default,,0000,0000,0000,,
Dialogue: 0,0:02:46.19,0:02:48.42,Default,,0000,0000,0000,,
Dialogue: 0,0:02:48.42,0:02:50.48,Default,,0000,0000,0000,,
Dialogue: 0,0:02:50.48,0:02:51.99,Default,,0000,0000,0000,,
Dialogue: 0,0:02:51.99,0:02:55.02,Default,,0000,0000,0000,,
Dialogue: 0,0:02:55.02,0:02:57.65,Default,,0000,0000,0000,,
Dialogue: 0,0:02:57.65,0:03:00.79,Default,,0000,0000,0000,,
Dialogue: 0,0:03:00.79,0:03:04.59,Default,,0000,0000,0000,,
Dialogue: 0,0:03:04.59,0:03:06.62,Default,,0000,0000,0000,,
Dialogue: 0,0:03:06.62,0:03:09.05,Default,,0000,0000,0000,,
Dialogue: 0,0:03:09.05,0:03:11.92,Default,,0000,0000,0000,,
Dialogue: 0,0:03:11.92,0:03:15.25,Default,,0000,0000,0000,,
Dialogue: 0,0:03:15.25,0:03:18.40,Default,,0000,0000,0000,,
Dialogue: 0,0:03:18.40,0:03:21.65,Default,,0000,0000,0000,,
Dialogue: 0,0:03:21.65,0:03:23.95,Default,,0000,0000,0000,,
Dialogue: 0,0:03:23.95,0:03:26.59,Default,,0000,0000,0000,,
Dialogue: 0,0:03:26.59,0:03:28.79,Default,,0000,0000,0000,,
Dialogue: 0,0:03:28.79,0:03:31.65,Default,,0000,0000,0000,,
Dialogue: 0,0:03:31.65,0:03:34.02,Default,,0000,0000,0000,,
Dialogue: 0,0:03:34.02,0:03:36.71,Default,,0000,0000,0000,,
Dialogue: 0,0:03:36.71,0:03:39.65,Default,,0000,0000,0000,,
Dialogue: 0,0:03:39.65,0:03:43.35,Default,,0000,0000,0000,,
Dialogue: 0,0:03:43.35,0:03:45.74,Default,,0000,0000,0000,,
Dialogue: 0,0:03:45.74,0:03:50.42,Default,,0000,0000,0000,,
Dialogue: 0,0:03:50.42,0:03:53.59,Default,,0000,0000,0000,,
Dialogue: 0,0:03:53.59,0:03:55.48,Default,,0000,0000,0000,,
Dialogue: 0,0:03:55.48,0:03:57.02,Default,,0000,0000,0000,,
Dialogue: 0,0:03:57.02,0:04:01.22,Default,,0000,0000,0000,,
Dialogue: 0,0:04:01.22,0:04:04.38,Default,,0000,0000,0000,,
Dialogue: 0,0:04:04.38,0:04:07.61,Default,,0000,0000,0000,,
Dialogue: 0,0:04:07.61,0:04:10.69,Default,,0000,0000,0000,,
Dialogue: 0,0:04:10.69,0:04:12.39,Default,,0000,0000,0000,,
Dialogue: 0,0:04:12.39,0:04:13.82,Default,,0000,0000,0000,,
Dialogue: 0,0:04:13.82,0:04:16.25,Default,,0000,0000,0000,,
Dialogue: 0,0:04:16.25,0:04:17.95,Default,,0000,0000,0000,,
Dialogue: 0,0:04:17.95,0:04:20.19,Default,,0000,0000,0000,,
Dialogue: 0,0:04:20.19,0:04:21.92,Default,,0000,0000,0000,,
Dialogue: 0,0:04:21.92,0:04:23.72,Default,,0000,0000,0000,,
Dialogue: 0,0:04:23.72,0:04:26.52,Default,,0000,0000,0000,,
Dialogue: 0,0:04:26.52,0:04:28.52,Default,,0000,0000,0000,,
Dialogue: 0,0:04:28.52,0:04:31.79,Default,,0000,0000,0000,,
Dialogue: 0,0:04:31.79,0:04:33.29,Default,,0000,0000,0000,,
Dialogue: 0,0:04:33.29,0:04:34.95,Default,,0000,0000,0000,,
Dialogue: 0,0:04:34.95,0:04:36.25,Default,,0000,0000,0000,,
Dialogue: 0,0:04:36.25,0:04:37.98,Default,,0000,0000,0000,,
Dialogue: 0,0:04:37.98,0:04:39.25,Default,,0000,0000,0000,,
Dialogue: 0,0:04:39.25,0:04:40.79,Default,,0000,0000,0000,,