Cho tam giác ABC có góc B = 90 độ. Đường cao BH, biết BH = 20 cm, HA = 15 cm. Tính tỉ số lượng giác của góc A, từ đó suy ra tỉ số lượng giác của góc C

Bày giúp em mấy bài em khoanh với ạ. Em xin cảm ơn

Tìm m,n nguyên dương biết A,2^m+2^n. B,2^m-2^n=256

Mọi người giải giúp em dk k ạ em đang cần ạ em cảm ơn m.n

viết đoạn văn ( 7 đến 10 ) dòng tóm tắt bài sự tích hồ gươm trong đó có sử dụng các từ mượn , hãy gạch chân những từ đó

41.look!you(make)...........the same mistake.of no. not again i always(make)..............that mistake 42.let me look at you.you(not change)............much since i met you 43.i(tell)................you about it when i have time 44.if you don't get up early,you(be).................late for school 45.would you like to go to the cinema tonight?yes,please.when..........we(meet).......? 46.why do you have pencil in your hand?i(draw)...................a cartoon 47.what do you want to be when you grow up?i(be)....................a teacher 48.ann(want)...............to see you.you(not see)................her for a long time 49.do you know where he lives?no , he recently(move).............to a new flat.i(not be) 50.they(be)..............there three months ago 51.........you(know)...........................eliza?yes.how long........you(know)........her? 52.mrs smith(work).............in the library since 1983 53.i've been in this city for a long time.i(come).......here sixteen years old 54.hurry up!we're waiting for you.what's talking you so long? i(wait)............for an important phone call.go ahead and leave without me 55.robert is going to be a famous someday.he(appear).........in three movies already 56.why did you buy all this some suger and chocolate?i(make)..............delicious dessert for dinner tonight 57.next week, when there(be)...................a full moon.the ocean tides will be higher 58.while i(watch)................tv last night , a mouse ran across the floor 59.the earth(depend)...............................on the sun for its heat light 60.ahh!i(try).............to concentrate.i can't hear myself think with all that noisy going on 61.mrs lien is at the market . right now she(look).............at the apples.they(look)...........fresh 62.nam(not hear)............his parents having a argument last night.he(listen)...............to music in his room 63.when i was a children,my brother always(serve)...........................cookies and milk to my friends and me when we(go)...........to my after school 64.jane is expecting a letter from me.but i(not write)..................to her yet 65.let's stop at the next motel.we(drive).................500 miles so far today and that's enough 66.everybody makes mistakes in life . i(make)..........lots of mistakes in my life.the important thing is to learn from one's mistakes.right? 67.i understand tom is good friend of yours?how long.....you(know).........him?since we(be).........kids 68.my wife and i(move)......three times since we(get).......married 5 VOTE+ CÂU TRẢ LỜI HAY NHẤT+ CẢM ƠN MK CẦN GẤP

Các anh chị bày giúp em những bài em khoanh với ạ. Em xin cảm ơn

1 he(sleep).........so he didn't understand what you said to him 2.some animals(not eat)..................................during the winter 3, why didn't you listen while i(speak)..............to you? 4.how many cigarettes...................you(smoke)............today? 5.It(be)...............hours since he left 6...........................you ever(see)..........................a ghost? 7.this time last year they(visit)..................................HLB 8.they(arrive)...................in a few minutes 9..............you(be)...........to england?yes,i(go).........there three years ago 10.of course,i'm not going to give her a gold ring.is i(give)...................her a gold ring , she(sell).............it 11.i(make)....................a cake when the light went out.i had to finish it in the dark 12.jack is trying to give up smoking.he(not have).......................a cigarette for a week 13.when he(return)...................i will give him the key 14.it's ages since we last(meet)......................... 15.i hope it(not rain)....................when the bride(leave)..................the church tomorrow 16.we were to late.the plane(take)...............off 10 minutes ago 17.if anybody(have)....................a question,please ask me after class 18.joe's pants were torn while he(climb)............................up the tree 19.we(live)......................in DAnang city for fourteen years 20.why are you turning the television?i(watch)..............................the news 21.i don't have any money.don't worry.i(lend)....................................you some 22.what would you like to drink tea or coffee?i(have).........................tea please 23.are you going shopping?yes,i(buy).....................something for dinner 24.we(not begin).........................to study for test yet 25.last night,i(arrive)................home at 12:30.i(have)..................a bath and then(go)............to bed 26.the car looks very clean................you(wash).............it? 27.it(rain)............now.it(start).............raining 4 hours ago.it(rain)...................for a 4 hours 28.everyday(read)..............................french newspapers,but when i(come).................to see her yesterday,(read)........................English magazines 29.he(not allow).................us to go in the boat yesterday as a strong wind(blow)...................... 30.you(look)..........................................very busy when i(see)..................you last night.what...........you(do)...? 31.she said the car(travel).............at 40 kilometers per hour when it(begin).............skind 32.at 6 o'clock this morning,she(do)...............morning exercise 33.i(return).............................the book as soon as i(finish)............reading it 34.i saw a light in your house as i(pass)................. 35.i(not eat)......................anything yesterday because i(not fell)............................hungry 36.what..............you(do)...............when i(see)............you?i was on my way home 37.don't worry.i(give)..................you a lift,i am sure you'll be at station in 10 minutes 38.could you be quiet please?i(listen)................to the radio 39.the children are late.they(not come)...................................home from school yet.i hope nothing's wrong 40.i decided not to go out because it(rain)............... 5 VOTE + CÂU TRẢ LỜI HAY NHẤT+ CẢM ƠN CHO BẠN NÀO NHANH NHẤT MK ĐANG CẦN GẤP

viết bài văn ngắn cảnh báo loài người về đại dịch covid 19

B=2015+ ║2014-2x ║ ║ là giá trị tuyệt đối