1: AD=8-2=6cm

AD/AB=6/8=3/4

AE/AC=9/12=3/4

=>AD/AB=AE/AC

2: Xét ΔADE và ΔABC có

AD/AB=AE/AC
góc A chung

=>ΔADE đồng dạng với ΔABC

3: AI là phân giác

=>IB/IC=AB/AC

=>IB/IC=AD/AE

=>IB*AE=AD*IC

1: Sửa đề: Qua N kẻ đường song song với PC cắt AB tại F

Xét tứ giác CNFP có NF//PC

nên CNFP là hình thang

a: Xét tứ giác AECF có 

AE//CF

AE=CF

Do đó: AECF là hình bình hành

1/4x+2/3x+4/3=0

11/12x=0-4/3

11/12x=-4/3

x=-4/3:11/12

x=-48/33

a: Xét tứ giác BFCE có

D là trung điểm của BC

D là trung điểm của FE

Do dó: BFCE là hình bình hành

b: Xét tứ giác ABFE có 

AB//FE

AB=FE

Do đó: ABFE là hình bình hành

mà \(\widehat{FAB}=90^0\)

nên ABFE là hình chữ nhật

1 from

Receive something from somebody: Nhận được thứ gì từ ai

2 with

Spend time with somebody: Dành thời gian với ai

3 at

Laugh at something: Cười cái gì

4 of

Sense of humor:  Khiếu hài hước

5 at - in

Dùng "at" với những đường có địa chỉ cụ thể.

Dùng "in" trước tên các thành phố, tỉnh, quốc gia.

1. I received a letter from my friend yesterday.
2. Khoi is my close friend. I spend most of my free time with him.
3. His friends didn't laugh at his jokes.
4. My friends usually enjoy my sense of humor.
5. He lives at 26 Tran Phu Street in Ha Noi.

e tk:

https://vietjack.com/van-mau-lop-7/images/so-do-tu-duy-duc-tinh-gian-di-cua-bac-ho-a01.PNG

Chuyển những câu này sang thể bị động:

We have just seen a horrible accident. …………A horrible accident has just been seen by us………………………………………………

What language do people speak in this country? ……………………What language is spoken in this country?…………………………

At 7 p.m., Mrs. Smith was making cakes. ……………………At 7 p.m, cakes are were being made…………………………………

He isn’t going to buy that house. ………………………That house isn't going to be bought…………………………………………

This terrorist has kept 3 hostages for a week. ………………3 hostages have been kept by this terrorist for a week……………………………………

He hasn’t seen you for years. ………………You haven't been seen for years……………………………………………………

The examiner will read the passage 3 times. ……………………The passage will be read 3 times by the examiner………………………………

An earthquake destroyed the town. ……………The town was destroyed by an earthquake………………………………………………

He didn’t type the letter last night. …………………The letter wasn't typed by him last light……………………………………………

They will pick me up at my house. ……………………I will be picked up at my house………………………………………

When did you see him in that bank? ………………………When was he seen in that bank?……………………………………

a: AN+CN=AC

=>AN=20-15=5cm

Xét ΔABC có AM/AB=AN/AC

nên MN//BC

b: Xét ΔAMN và ΔNPC có

góc AMN=góc NPC(=góc B)

góc ANM=góc NCP)

=>ΔAMN đồng dạng với ΔNPC