Cho ABC có AB= 12cm, BC = 20cm. Kẻđườngcao AH

a.Tính AC, AH, BH, CH?

b.KẻHD ⊥AB tại D, HE ⊥AC tại E. Chứngminh: AD.AD = AE.AC = BH.HC

.c.Chứng minh: AD.BD = AH ² - AD²

d.Chứngminh:AE.EC+AD.BD=AH²

Cho ABC có AB= 12cm, BC = 20cm. Kẻđườngcao AHa.Tính AC, AH, BH, CH?b.KẻHD ⊥AB tại D, HE ⊥AC tại E. Chứngminh: AD.AD = AE.AC = BH.HC.c.Chứng minh: 22.ADBDAHAD=−d.Chứngminh: 2..AEECADBDAH+Cho ABC có AB= 12cm, BC = 20cm. Kẻđườngcao AHa.Tính AC, AH, BH, CH?b.KẻHD ⊥AB tại D, HE ⊥AC tại E. Chứngminh: AD.AD = AE.AC = BH.HC.c.Chứng minh:Cho ABC có AB= 12cm, BC = 20cm. Kẻđườngcao AHa.Tính AC, AH, BH, CH?b.KẻHD ⊥AB tại D, HE ⊥AC tại E. Chứngminh: AD.AD = AE.AC = BH.HC.c.Chứng minh: 22.ADBDAHAD=−d.Chứngminh: 2..AEECADBDAH+

1. Choose the correct word that has the different stress from the others. A. enjoy B. impress C. depend D. beauty 2. Choose the correct word that has the underlined part pronounced differently from the others. A. beautify B. country C. friendly D. activity 3. I wish you ___________here with me now. A. are B. were C. was D. being 4. Tom wishes he _____________there someday. A. Will be B. should be C. would be D. must be 5. My sister had difficulty __________the English test last Monday. A. did B. doing C. was doing D. done 6. Mr. Nam used ____________on a farm in the countryside. A. lives B. living C. lived D. to live 7. The Singapore unit of _____________is dollar. A. time B. volume C. currency D. field 8. Islam is Malaysia’s official _____________. A. government B. religion C. region D. language 9. Maryam and Lan have ___________for five years. A. corresponding B. correspond C. corresponds D. corresponded 10.English and math are ____________subjects in our school. A. compulsory B. national C. additional D. traditional 11.Many tourists are really ____________by the beauty of Hanoi. A. impress B. impressive C. impression D. impressed 12.Mai’s religion is Buddhism, so she goes to _________every day. A. mosque B. pagoda C. church D. countryside 13.You are rather old, you should not depend too much _______your parents. A. on B. in C. of D. with 14.In some ways, Kuala Lumpur is not different ___________Hanoi. A. in B. on C. of D. from 15._______Mary learnt very hard, she passed the exam easily. A. and B. or C. because D. so 16.English is a /an ___________ language. It is spoken widely in the world. A. international B. national C. native D. nationwide 17.Miss White is very friendly, ___________everyone loves her. A. so B. because C. while D. when 18.Malaysia is divided ___________two regions. A. to B. in C. out of D. into 19.Almost all the tourists want to go back to Hanoi because of the people’s __________. A. friendship B. friendliness C. unfriendliness D. friendlessness 20.Although Nam lives far from his girlfriend, he tries to _______her. A. get touch on with B. keep in touch with C. keep on with D. keep away with 

Cho 6,1975 lít khí SO2(đktc) tác dụng vừa đủvới ddBa(OH)22M

a) Viết PTHH 

b) Tính khối lượng muối tạo thành 

    c) Tính thểtích dung dịch Ba(OH)2cần dùng ?                       

    (Biết  Ba = 137  ,  H = 1  ,  S = 32  ,  O = 16 )