How many integer solutions does the following equatios have?
(x2 - x - 1)x+2000 = 1
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Cộng từng vế ta có: (x2 - y) + (x2 + y) < 1 + 4
=> 2.x2 < 5 => x2 < 2,5 . vì x nguyên nên x2 = 0 hoặc 1
+) x2 = 0 =>x = 0 và -y < 1 và y < 4 => 4 > y > -1. vì y nguyên nên y = 0; 1;2; ;3
vây (x; y) = (0;0); (0;1); (0;2) ;(0;3)
+) x2 = 1 => x = 1 hoặc -1 và 1- y < 1 ; 1 + y < 4 => y > 0 và y < 3 => 0 < y < 3. vì y nguyên nên y = 1; 2;
vậy (x; y) = (1; 1); (1; 2) (-1;1); (-1; 2)
vậy...
=> x^2 - y + x^2 + y =< 5
=> 2x^2 < 5
=> x^2 <2,5
=> x = { -1;0;1} ( vì x nguyên)
(+) x = -1 => 1 - y < 1 => y > 0
1 + y < 4 => y < 3
=> 0 < y < 3 => y = 1 ;2
có hai cặp ( -1 ; 1 ) ; ( -1 ; 2 )
Tương tự
61. How many childs does your mother have?
A. many B. childs C. does D. have
62. There is many good restaurants and amusement parks in our neighborhood.
A. There is B. restaurants C. and D. in
63. He must makes his bed after he wakes up every day.
A. makes B. bed C. wakes up D. every day
64. She always give presents to her parents on Tet holiday.
A. give B. to C. her D. on
65. You must walk on grass when you see the sign “No walking”.
A. must B. on C. see D. the sign
66. Shall we having a picnic by the sea tomorrow?
A. Shall B. having C. a D. by
67. This movie is worser than that one.
A. This B. is C. worser D. one
68. Ha Long Bay is one of the much natural wonders in Viet Nam.
A. is B. of C. much D. natural wonders
69. In my opinion, city life is as exciting than country life.
A. In B. city life C. as D. exciting
70. They are healthy because they play yoga every day.
A. are B. healthy C. because D. play
III. Choose the underlined part that needs correction in each of the following questions.
61. How many childs does your mother have?
A. many B. childs=> children C. does D. have
62. There is many good restaurants and amusement parks in our neighborhood.
A. There is => there are B. restaurants C. and D. in
63. He must makes his bed after he wakes up every day.
A. makes=> make B. bed C. wakes up D. every day
64. She always give presents to her parents on Tet holiday.
A. give => gives B. to C. her D. on
65. You must walk on grass when you see the sign “No walking”.
A. must=> must not B. on C. see D. the sign
66. Shall we having a picnic by the sea tomorrow?
A. Shall B. having=> have C. a D. by
67. This movie is worser than that one.
A. This B. is C. worser=> worse D. one
68. Ha Long Bay is one of the much natural wonders in Viet Nam.
A. is B. of C. much=> best D. natural wonders
69. In my opinion, city life is as exciting than country life.
A. In B. city life C. as=> more D. exciting
70. They are healthy because they play yoga every day.
A. are B. healthy C. because D. play => do
There are 4 rooms in my house
I have 10 pens
I have 2 brothers
My school has 3 floors
He goes to school at 7a.m
I get up at 6a.m
She washes her face at 8a.m
I brush my teeth at 10p.m
I have breakfast at 6.45
He does morning exercise at 6.30
1 many => much
2 an => a
3 eating => eat
4 am => are
5 do => does
5 go = >goes
many -> much
an -> a
eating -> eat
am -> are
do -> does
go -> goes
Đảm bảo đúng nha bạn
1.many to much
2.much to many
3.pencil to pencils
4.are to is
5.does to do
6.has to have
7.sister many to many sister
8.there are to are there
9.there is to is there
tick nha
1 many => much
2 much => many
3 pencil => pencils
4 are => is
5 does => do
6 has => have
7 sisters many => many sisters
8 there are => are there
9 there is => is there
1. How many classes does your school ?
2. Linda has many lots of friends because she friendly .
3. James smokes but his brother doesn't
1. How many teachers are there in your school?
=> How many teachers does ......................................your school have?..........................................................................
2. The photocopy store is to the left of the movie theater.
=> The movie theater is…….………………is to the right of the photocopy store………………………….………………..……….……
3. Ho Chi Minh City is bigger than Ha Noi.
=> Ha Noi ………………….……is not as big as HCMC…..…………………………………..……………..………….….
4. Dung is Mrs. Hoa’s granddaughter.
=> Mrs. Hoa……………………is Dung's grandmother ..………………………………………………………..……….…..
5. Why don’t we go to the movies tonight?
=> What ...................................about going to the movies tonight?.............................................................................................................
6. What is the price of this dictionary?
=> How............................does this dictionary cost?.....................................................................................................................
7. What’s your favorite drink?
=> What drink………………do you like most?…………………………………………………………...……………
8. Nobody in my class is taller than Hieu.
=> Hieu……………is the tallest in my class……………………………………………………………….…………....…….
9. Dr. Kim drives his car to work every morning.
=> Dr. Kim goes.............................to work by car every morning.......................................................................................................
10. The subject Nam likes most at school is English.
=> Nam’s …………………………favorite subject is English…………………………………………………………………...
11. In spite of taking a taxi, he arrived late for the meeting.
- Although ________he took a taxi, he arrived late for the meeting_________________________ .
12. It is such a heavy box that I can't carry it.
- The box is ______so heavy that I can't carry it_____________________________ .
tui xem tất cả các bài toán lop 8 hôm nay, mỗi bài này hay nhất mà đăng 6h rùi k ai làm dc hả
đơn giản,bn chỉ cần nhớ ct; ao =1
ta có x+2000 = 0 => x = -2000
( nếu bài này ở nuoc ngoài thì họ giỏi thât, họ hơn đứt giáo dục vn)