Cho hình bình hành ABCD. Trên cạnh CD và BC lấy M, N sao cho BM = DN. Gọi I là giao điểm của BM và DN. CMR: IA là tia phân giác của DIB.

Giải phương trình:

a. \(x^4+7x^2-12x+5=0\)

b. \(3|x-3|-2|x-2|+|x-1|=4\)

Make sentences:

1. If / sister / not / take care / the garden everyday / there / not / flowers.

2. Households / dump / waste / river / so / it / polluted.

3. The boys / have / stop / play / volleybal / because it / rain / heavily.

4. If / weather / fine, they / go / picnic.

5. If I / be / father, I / buy / new car / travel.

6. Polluted water / lead / death / fish / lake.

7. Mother / tired, so she / not / go / work.

8. If / sister / do / exercise. he / be / healthier.

9. If / there / be / no fresh water what / happen.

10. People / get / more diseases if water / contaminated.

11. Acid rain / make / plant / die.

Mn giúp mk vs. Mk ko xác định đc viết câu nào là đk loại 1 hay 2 nữa. HELP <E.

Rewrite the sentences:

1. Because it rained heavily, the city was flooded.

=> Due to ............................................................

2. His legs were injured, so he couldn't go to school.

=> Because / Since.................................................

=> Because of .......................................................

3. Lan had a cold because she played in the rain all the day.

=> Lan played.....................................................................

=> Due to ...........................................................................

4. Tan isn't free, so he can't help you.

=> If .................................................

5. Due to the heavy storm, the students didn't go to school.

=> Because .......................................................................

6. The water is polluted, so the fish are dead.

=> The polluted water...................................

=> The polluted water leads ........................

7. We can't see the stars at night because there is much light pollution.

=> If ......................................................................................................

8. People throw rubbish in the streets. The streets don't look attractive.

=> If ......................................................................................................

Choose the best answer:

1. The acid rain has caused ... to the trees in this area (dead / damage / pollute / contaminate)

2. Peope ... New Zealand into the north Island and the south Island

(divides / divided / have divided / are dividing)

Cho hình bình hành ABCD, với AC > DB. Gọi E, F lần lượt là chân đường vuông góc kẻ từ C tới AB, AD. CMR: AB . AE + AD . AF = AC²

Cho tam giác đều ABC. Gọi M là 1 điểm bất kì nằm trong tam giác. CMR: tổng các khoảng cách từ M đến 3 cạnh của tam giác có giá trị không đổi khi M thay đổi vị trí trong tam giác.