Rút gọn: a) (a^2+b^2-c^2)-(a^2-b^2+c^2)^2 b) (a+b+c)^2+(a+b-c)^2-2.(a+b)^2 c) (a+b+c)^2+(a-b+c)^2+(a+b-c)^2+(b+c-a)^2

Mình xin hỏi 3 câu trong hình ạ (20,21,22), hy vọng đc chi tiết.

(1+4+7+...+97+100)x X=17 làm hộ mình với

Mọi ng giúp mk vs ạ. Có cả lý thuyết ảnh 1 nhé ạ. Mong mn giúp

11. You work very hard. I’m sure you’ll have no _______ the exam . A. difficulties of passing B. difficulty passing C. difficulties to pass D. difficulty to pass 12. _____________________ director must have surprised all the staff. A. You nominated B. Your being nominated C. You have been nominated D. Your nominating 13. This is such an important question that we can’t _________________thinking it over. A. point B. use C. help D. stand 14. ________________ the Christmas shopping season begins. A. That is after Thanksgiving B. After Thanksgiving it is C. It is after Thanksgiving that D. It is Thanksgiving that 15. My new glasses cost me _______ the last pair I bought last month. A. more than three times B. three times as much as C. more three times than D. as much three times as 16. You will find their house __________ you take a good street map with you. A. as long as B. even if C. unless D. otherwise: 17. By the end of last March, I _____ English for five years. A. was studying B. would be studying C. has been studying D. had been studying 18. You’d better stop spending money, _______ you will end up in debt A. unless B. otherwise C. if D. in case 19. The people in my class, _____ are very friendly. A. most of international students B. the most international students C. almost international students D. mostly international students 20. He is determined to finish the job _____________ long it takes A. whenever B. whatever C. no matter D. however

Giúp mk 3 bài cuối thôi ạ.3 bài thôi mà tận 60 điểm ạ.💮💮💮💮💙💙💙💙💙🌺🌺🌺🌺

Chứng minh sự so sánh về bất đẳng thức

Tính nhanh $\frac{74×76-196}{72×74+100}$

B1: Tính 1) (a+b+c)^2 2) (a+b-c)^2 3) (a-b+c)^2

11. You work very hard. I’m sure you’ll have no _______ the exam . A. difficulties of passing B. difficulty passing C. difficulties to pass D. difficulty to pass 12. _____________________ director must have surprised all the staff. A. You nominated B. Your being nominated C. You have been nominated D. Your nominating 13. This is such an important question that we can’t _________________thinking it over. A. point B. use C. help D. stand 14. ________________ the Christmas shopping season begins. A. That is after Thanksgiving B. After Thanksgiving it is C. It is after Thanksgiving that D. It is Thanksgiving that 15. My new glasses cost me _______ the last pair I bought last month. A. more than three times B. three times as much as C. more three times than D. as much three times as 16. You will find their house __________ you take a good street map with you. A. as long as B. even if C. unless D. otherwise: 17. By the end of last March, I _____ English for five years. A. was studying B. would be studying C. has been studying D. had been studying 18. You’d better stop spending money, _______ you will end up in debt A. unless B. otherwise C. if D. in case 19. The people in my class, _____ are very friendly. A. most of international students B. the most international students C. almost international students D. mostly international students 20. He is determined to finish the job _____________ long it takes A. whenever B. whatever C. no matter D. however