Trộn V ml dd NaOH 0,1M với 200ml dd HCl 0,1M. Sau phản ứng thu được dd có pH= 12. Tính V?

Sin^3x +3cos2x + 11sinx - 9 =0 Sin2x + 12(cosx - sinx) = -12 Sin^2x - 10sinx.cosx +21cos^2x =0

Giúp mình bài trắc nghiệm đi , cảm ơn

tính CM của dd NaOH vầ dd H2SO4 biết + nếu lấy 60ml dd NaOH thì trung hòa hoàn toàn 20ml dd H2SO4 + nếu lấy 20ml dung dịch H2SO4 tác dugj 2,5g CaCO3 thì muốn trung hòa lượng axit dư phải dùng hết 10ml dd NaOH ở trên

1. Last month our class (go) ____________ on a field trip with our teacher. We (not have) ____________ another field trip since then. 2. I (use to/ live) ____________ with my grandmother until I (be) ____________ 18. Since then, I (meet) ____________ my grandmother again. 3. My mother (work) ____________ as a teacher in the local high school for 20 years before her retirement. 4. The last time we (have) ____________ dinner together was 2 weeks ago. 5. My uncle (meet) ____________ his family since he (go) ____________ on a business trip last month. 6. Your friend Sarah (just/ phone) ____________ you. She (say) ____________ sorry because she (can/ come) ____________ to your party. 7. So far, I (already/ read) ____________ 11 different books. My most favourite book is “Paper towns” by John Green. I (finish) ____________ reading it last weekend. 8. Last night I (feel) ____________ well, so my father (take) ____________ me to hospital. I (be) ____________ out of hospital yet. NHANH HỘ EM

sử dụng từ trong ngoắc diền vào chỗ trống practice word formation 1. She ...................... us English at school. (TEACHER) 2. In my ......................, there is a park. (NEIGHBOR) 3. Bacgiang has a lot of ................. places. ( BEAUTY ) 4. What is the .................. of this mountain? ( HIGH) 5. We often buy cheap bread in the .................. (BAKE) 6. They have a lot of ........................ in the summer. (ACT) 7. This is the ....................... pagoda in Bacgiang ( OLD) 8. Don't ride too quickly. It is ......................... (DANGER) 9. My house is .................. than yours. (BIG) 10. He greets me in a ......................... way. (FRIEND) There are four............................in my house. (bookshelf.) The photocopy is between the .........and the drugstore. (bake) Is your brother an .........................................? (act) Mai's sister is a ...................................... (sing) We must be ................ when we cross the road. (care) This tree has a lot of green .......................................... (leaf) Is your father a .............................................? ( business) I’m Vietnamese. What’s your ....................................? (nation) Air ................. is a big problem in many cities in the world. (pollute) Yoko is from Japan. She is ................................ (Japan) Anna likes attending the English ................... contests. (SPEAK) My neighborhood is .............. for good and cheap restaurants. (FAME) I like the city life because there are many kinds of ...............(ENTERTAIN) Van’s classroom is on the ......................................... floor. (TWO) These children like ........................................ weather. (SUN) Lan speaks English ....................................... than me. (WELL) The Great Wall of China is the world’s ................. structure. (LONG) What’s Maco’s ........................................? - She’s British. (NATION) Don’t make a fire hare. It’s very……….. (DANGER.) Air…….. is a big problem in many cities in the world. (POLLUTE) There are lot of……………mountains in Vietnam (BEAUTY.) I’m Vietnamese. What’s your…………? (NATION) This is the ………….. pagoda in our country (OLD). She is very ……………….. . (beauty) Mai’s sister is a ………………… . (sing). It is very ………........... in the city. (noise) Her …………….. are small and white. (tooth) There are two ……………… in his office. (secretary) Do you know the …………….. of this book? (write) This is my favorite chair. It’s so …………….. . (comfort) My father often ………………. his work at 4.30. (finish) The Mekong River is the …………._ river in Vietnam. (long) Tokyo is …………………. than London. (big) Ho Chi Minh city is the………………….city in Vietnam. (big) Petronas Twin Towers is…………….than Sears Tower. (tall) My sister is …………………. than I. (old) Nam is……….than Ba. He is the ………_ boy in Vietnam. (short) Phanxipang is the …………………. mountain in Vietnam. (high) These books are …………………. than those books. (thick) It is the………………….building in this city. (tall) The Nile River is …………………. than the Amazon River. (long)

giải hộ mình 3 câu khoanh tròn ạ

40^2-39^2+38^2-37^2+....+2^2-1^2

Giúp mik vs ạ Mik cảm ơn nhiều :<

Phân tích đa thức thành nhân tử 4x^2y^2-(x-y)^2