Cho đa thức f(x) = x^3 + ax^2 – bx + 2.
a) Cho a = -1/2 và b = 4. Chứng minh rằng x = 1/2 là nghiệm của đa thức.
b) Biết đa thức đã cho nhận x = 1 và x = -2 là nghiệm. Tìm giá trị của a và b?
c) Với đa thức tìm được ở câu b, hãy tìm giá trị của x thỏa mãn f(x) = x + 2.
the present perfect tense
1.I(be)......................a wake since 4 o'clock.
2.Mr.Pike (live)............................here since last october.
3.We (not see).........................them for a long time.
4.my father (not smoke)...........................for a long time.
5.george (work).............................at the university so far.
6.how long .......................you(practise)..........................piano?-I(practise)......................it since 10a.m
7.I(work)...................at my report since Monday
8.i(collect).......................stamps since i was a child
9. ....................you ever (be)..........................to HCM city?-Yes,i(go)..........................there last month
10.since they(go).........................away,they(not contact)........................to theirb family
11.we (not do).............................anything since we (arrive)......................here
12. ........................you ever(visit).........................Hue city?-yes,i(visit)........................it 3 years ago
13.i(not wear).................that suit since my sister (marry)......................
14.Minh just(win).............................the first prize in the talent contest
giúp mk nhé
the present perfect tense
1.what .................Thao just(do)............................?-she(write)............................a letter
2.how long ..............you(play).............................guitar?-i(play)............................it for 2 hours
3.he (not have)...........................cigarettes for week
4.i (not see).............................him for month.
5.they(be)..............................famous in my country for years .
6.we(live)..............................in this flat since we got married
7.i(know)............................that for a long time
8.she (drive).........................the same car since1999
9.i (play)...............................tennis since last month
10.he(not eat).............................anything for twenty four hours
the present perfect tense
1.sorry i (not write)...........................to you for a long time.
2.they moved to Ho Chi Minh city in 1999 and (live)......................there since then
3.i don't think ever(meet)......................each other before
4.john and i (be)........................pen pals for nearly three years
5.she says titanic in the bast film she ever ( see).................. .
6.jack is traying to give up smoking .He (not have)...........................cigarettes for a week
7.how long you(read)............................that book?- i (read).........................it for a week
8.i'm hungry because i (not have)..............................breakfast of lunch yet
9.we just (send)......................her a new pen.
10.i (try)................................. to learn english for years,but i (not succeed)....................yet
I.the simple past tense
1.i (meet).....................Hoa yesterday
2. he (work)...................in that bank four years ago
3.i(see)..........................a lot of beautiful fish at Tri Nguyen Aquarium last summer
4.they (go).............................to Ha Long for their last summer vacation
5.my friend(take).....................me to see Tay Phuong pagoda
6.we(speak).........................to some American tourists
7.she(receive)......................a lot of gifts on her birthday
8.lan(buy).....................a yellow cap,and she (wear).......................it all day
9.i(be).......................in Ho Chi Mnh city for a short visit
10.he (returm).......................to America for a short visit
11. my teacher(teach).......................me to love animals
12.they (be)................................very happy in Viet Nam in spring festival
13.Ba (borrow)...........................the tools from his friend
14.my father and i (make)................................pencil box
15.Lan(decorate)..........................her room with silver and yellow and pink flowers yesterday
16.we (lear)..............................how to repair household appliances at school last week
17.Mrs.Mai(lear)...............................how to repair her dress
18.they (remember)...........................their vocation inNha Trang last summer
19.i (arrive)..........................home at 11o'clock last night
20.we(talk)...........................about our teacher about our plan for this summer vacati on
21.Nam (not want)...............................to study.He(watch)....................TV instead
22. we (decide)...........................to visit one Hundred partitioned pagoda
23.liz (like).....................................to eat meat but she (not like)........................to eat fish
24.liz (receive)...................................many letters from her friends in the USA
giúp mk với
passive
I.Affirmative
1.Someone is sweeping the floor.
2.I am fixing my car.
3.Huy is listerning to music at the moment.
4.Miss Hai is teaching English at 9o'clock.
5.Vinh and his friends are drawing pictures very nice.
6.Lan is playing the piano in the sports centre.
7.Quynh and Phuong Anh are taking photos at the zoo.
8.Lam is watering the flowers at the moment
làm ơn giúp mk với
I interrogative pasive voice
1 are you doing morning exercise now?
2 is he closing the door at the moment?
3 is your mother eating break fast now?
4 is she writing a letter for her friends?
5 what books are you reading?
6 is your brother playing foot ball at the moment ?
7 is Lam playing games in the sport centre now?
8 are you making coffee at home now?
9 is Lan sweeping the school yard now?
10 is Vinh brushing his teeth in the bathroom at the moment
giúp mk với chiều nay mk kiểm tra rồi