1.Tim cac so tu nhien x sao cho:

a/6 chia het cho (x-1)                                      b/14 chia het cho (2.x+3)

2.Ve hinh de thay rang moi cau sau day la sai

a/Hai tia chung goc luon la hai tia doi nhau

b/Hai tia chung goc luon la hai tia trung nhau

c/Hai tia chung hoc luon la hai tia phan biet

d/Hai tia co nhieu diem chung chi khi chung la hai tia trung nhau

e/Hai tia phan biet va co chung goc luon la hai tia doi nhau

f/Hai tia ko chung goc luon la hai tia khong co diem chung

3/

a/Ve 3 diem thang hang A,B,C sao cho diem B nam giua hai diem A,C.Sau do hay ke ten:cac tia,cac cap tia doi nhau,cac cap tia phan biet,cac cap tia trung nhau co trong hinh ve do.

b/Ve 4 diem A,B,C,D tren mot duong thang sao cho diem B nam giua hai diem A,C va diem C nam giua hai diem B,D.Sau do hay ke ten:cac tia,cac cap tia doi nhau,cac cap tia phan biet,cac cap tia trung nhau co trong hinh ve do.

~~~~~~~~~~~~~Giup tui voi!!!!!~~~~~~~~~~~~~~

Cau 5: Trong cac khang dinh sau, khang dinh nao dung, khang dinh nao sai?

1.Ba diem phan biet la ba diem thang hang.

2.Voi ba diem phan biet luon co hai diem nam ve cung phia doi voi diem con lai.

3.Voi ba diem thang hang phan biet luon co hai diem nam khac phia voi diem con lai.

4.Voi ba diem A,B,C thang hang thi diem B luon nam giua hai diem A,C.

5.Co mot va chi mot duong thang di qua hai diem (phan biet) cho truoc.

6.Hai duong thang phan biet thi song song voi nhau.

7.Hai tia chung goc thi cung nam tren mot duong thang.

8.Hai tia chung goc thi doi nhau

9.Neu diem M nam giua diem A,B thi no la trung diem cua doan thang AB.

10.Neu MA=MB thi M la trung diem cua doan thang AB.

11.Neu MA+MB= AB va MA=MB thi M la trung diem cua doan thang AB.

Xin chao cac ban,cac gia su.Hom qua,minh co mot bai toan lop7 chua lam duoc,bay gio da co cau tra loi-cam on ban Lai Tri Dung nhe.Bay gio,minh co mot cau hoi nua,mong moi nguoi chi giup minh a!

   CHO tam giac ABC can tai A.Ve AH vuong goc voi BC tai H.

a)Cho biet AH=8cm.Tinh do dai doan thang BH.

b)Chung minh rang:tam giac HAB=t/giac HAC

c)Goi D la diem nam tren doan thang AH.Tren tia doi cua tia DB lay diem E sao cho DE=DB.CMR:AD+DE>AC.

d)Goi K la diem tren doan thang CD sao cho CK=2/3CD.CMR:3 diem H,K,E thang hang

   Minh mong la co cau tra loi

 som nhat. CAM ON NHIEU LAM AAAAAA!