`ĐKXĐ:x\geq0;x\ne0`
`(\frac{1+a\sqrt{a}}{1+\sqrt{a}}-\sqrt{a})(\frac{1+\sqrt{a}}{1-a})^{2}`
`=[\frac{(1+\sqrt{a})(1-\sqrt{a}+a)}{1+\sqrt{a}}-\sqrt{a}][\frac{1+\sqrt{a}}{(1+\sqrt{a})(1-\sqrt{a})}]^{2}`
`=(1-\sqrt{a}+a-\sqrt{a})(\frac{1}{1-\sqrt{a}})^{2}`
`=(1-2\sqrt{a}+a).\frac{1}{(1-\sqrt{a})^{2}}`
`=(1-\sqrt{a})^{2}.\frac{1}{(1-\sqrt{a})^{2}}`
`=1`
Vậy với `x\geq0;x\ne1` thì bth`=1`
Điều kiện xác định $x\ge 0, x\ne 1$
$\begin{array}{l} \left( {\dfrac{{1 + a\sqrt a }}{{\sqrt a + 1}} - \sqrt a } \right).{\left( {\dfrac{{1 + \sqrt a }}{{1 - a}}} \right)^2}\\ \left[ {\dfrac{{\left( {\sqrt a + 1} \right)\left( {a - \sqrt a + 1} \right)}}{{\sqrt a + 1}} - \sqrt a } \right].\dfrac{{{{\left( {1 + \sqrt a } \right)}^2}}}{{{{\left( {1 - a} \right)}^2}}}\\ \left( {a - \sqrt a + 1 - \sqrt a } \right).\dfrac{{{{\left( {1 + \sqrt a } \right)}^2}}}{{{{\left( {1 - a} \right)}^2}}}\\ = {\left( {\sqrt a - 1} \right)^2}.\dfrac{{{{\left( {1 + \sqrt a } \right)}^2}}}{{{{\left( {1 - a} \right)}^2}}}\\ = \dfrac{{{{\left[ {\left( {\sqrt a - 1} \right)\left( {\sqrt a + 1} \right)} \right]}^2}}}{{{{\left( {1 - a} \right)}^2}}}\\ = \dfrac{{{{\left( {a - 1} \right)}^2}}}{{{{\left( {a - 1} \right)}^2}}} = 1 \end{array}$
Cho hai điện tích điểm $q_{1} = 8.10^{-8}, q_2 = -8.10^{-8}$ C lần lượt đặt tại hai điểm A và B trong chân không cách nhau một khoảng AB = 6 cm. Xác định lực điện tổng hợp tác dụng lên điện tích điểm $q_{o}= 8.10^{-8}$ C đặt tại: a) Điểm I, với AI = 4 cm, BI = $2\sqrt[]{5}$ cm b) Điểm K, với AK = BK = 5 cm. c) Điểm H, với H nằm trên trung trực của AB và cách trung điểm của AB đoạn h = 7 cm
Câu 8: Lớp 5 A có 48 HS : a. Số HS giỏi chiếm 37,5 % . Hỏi lớp đó có bao nhiêu em đạt điểm giỏi? b. Lớp có 6 em loại TB. Số HS TB chiếm bao nhiêu % số HS của cả lớp? cứu..........
Trong các trường hợp nào ta có: (a+b) ²=a ²+b ²
II. Put the words : “am/ is/ are/ do / does” to complete the sentences: 1. This ……… Thu. She ……… my friend. 5. My brother and my sister …………. teachers. 2. How old ……. your father? 6. What ………. you do? 3. What …………. she do? 7. Who …………this? 4. How …………. you? – I ………… fine, thanks. 8. What ………. these? III. Put the verbs in brackets into the present simple tense. 1. She ___________ not (drink) the coffee. GV: NGUYỄN THỊ LAN HƯƠNG She ___________ (drink) Coca Cola. 2. It ________ (be) often hot in the summer. 3. What ______ you _______ (do) in the evening? 4. The earth __________ (circle) the sun once every 365 days. 5. I ___________ (see) her very often. 6. Most of rivers ___________ (flow) into the sea. 7. She __________ (wash) clothes twice a week. 8. He _______ (be) a teacher of English. He ____________ (teach) very well. 9. She never __________ (do) anything that I ___________ (not, like). 10. They ______________ (not, have) a bicycle, so they ______________ (walk) to school everyday. 11. She ____________(study) hard every day. She ________(want) to be a doctor in the future. 12. He ____________(like) drinking coffee in the morning. 13. My father always ____________(encourage) me to work hard. 14. She was born in Ha Noi but she ___________(live) in Hue now. 15. He __________(speak) very fluently. IV. Put the verbs in brackets into the present simple tense: 1. She (like)___________listening to pop music at night? 2. You (water)__________ the plant every morning? 3. Mr Minh (teach)___________you English? 4. He (fly)____________to Brazil every year? 5. They always (finish)___________their homework before going to bed? 6. She rarely (buy)___________meat for meal? 7. He (not like)______________seafood. 8. They won’t teach you if you (not obey)________________ them. 9. They (not walk)_____________at night. 10. We (not understand)_________________ what you are saying. 11. They won’t go shopping if they (not have)_____________much money. 12. He (not rest)_____________after lunch time. 13. They (not swim)______________as well as we expect. 14. She (not go)____________to the movie on Friday. 15. We (not know)______________how to use this car. 16. They (be)_____________American? 17. She (be)_____________happy in her own life. 18. This (be)_____________the most beautiful girl that you have ever seen? 19. You (be)___________tired? 20. There (be)____________ a lot of people in the meeting room? V. Give the correct form of the verb in parentheses: 1. What time................... you (start)...................... your classes? 2. My sister (have)..........................breakfast and (go) .........................to school at 6:30 every morning. 3. We (not read) ...........................................books after lunch. 4. Tom (be)................... my friend. He (play)..................... sports every day. 5. ...................your students (play).......................soccer every afternoon? 6. .....................your father (go)........................ to work at eight o’clock? 7. She (watch)..........................television every day. 8. There (be).......................twenty classrooms in my school. 9. Where …………….you (live)………………….? - I (live)……………………in Ho Chi Minh City. 10. – What ……………she (do)……………….? – She (be)……………….a teacher. 11. ………………you (be)……….in class 5A? – No, I (not be)…………………… 12. In summer, Lan often (go)…………………to the park with her friends. 13. I (have)………………….lots of homework at the weekend so I (be)………………..very busy. 14. How often ……………..you (have)…………………today? GV: NGUYỄN THỊ LAN HƯƠNG 15. She (not like)………………………music. 16. He usually (watch)……………………..TV after dinner. 17. There (be)…………………forty students in my class. 18. I (like )__________________ice-cream. 19. We (go) ______________to market and (buy)_________________some fruits. 20. Every night , she (have)____________________dinner at 7.00 p.m. 21. Every year, I usually (go)______________________Vietnam. 22. In the summer, I sometimes (go)____________________swimming. 23. Every evening, my mother (like)___________ watching television. 24. Lan (have)_______________breakfast and (go)___________to school at 6.30 a.m. 25. We (not read)___________________after lunch. VI. Complete the sentences using the right present simple form of the following verbs: check arrive start stop leave meet take get reach have 1. The trip …………………..on Friday morning. 2. Everybody …………………..on the coach by six o’clock a.m. 3. The coach ……………………at a roadside restaurant at 7.30. 4. We …………………….breakfast and get on the coach again after 30 minutes. 5. We ………………..in Phan Rang at about 11.30 and have lunch there. 6. The coach …………………..for Nha Trang at 12.00. 7. We ……………………Nha Trang at about 2.00 p.m 8. Everybody …………………….in at the hotel then. 9. You ……………………..a short rest after checking in. 10. We …………………..again for dinner at 6 p.m.
mn hãy giúp em nhanh đi hãy giúp em nahnh đi mn
Tìm nghiệm của 3x^2+2x-5 X^2-x+1
Trả lời + Giải thích giúp em ạ :<
''tobe" và "to be" cách viết nào đúng? giúp mình ạ cho hay nhất
120-1/2.40.4.1/5.20.1/4-20 tất cả trên 1+5+9.......+33+37+41
a) với n là STn chẵn ,chứng minh :(20^n+16^n-3^n-1) chia hết cho 323 b)
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