K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Các câu hỏi dưới đây có thể giống với câu hỏi trên
9 tháng 12 2017
a. \(\dfrac{\left(x^2+2x\right)}{\left(x+2\right)^2}=\dfrac{x\left(x+2\right)}{\left(x+2\right)\left(x+2\right)}=\dfrac{x}{x+2}\)
b. \(\dfrac{x^2-7x+12}{x^2-6x+9}=\dfrac{x^2-3x-4x+12}{\left(x-3\right)^2}\)
\(=\)\(\dfrac{x\left(x-3\right)-4\left(x-3\right)}{\left(x-3\right)\left(x-3\right)}=\dfrac{\left(x-4\right)\left(x-3\right)}{\left(x-3\right)\left(x-3\right)}=\dfrac{x-4}{x-3}\)
c. \(\dfrac{x^2-5x+6}{x^2-x-2}=\dfrac{x^2-2x-3x+6}{x^2-2x+x-2}\)
\(=\dfrac{x\left(x-2\right)-3\left(x-2\right)}{x\left(x-2\right)+\left(x-2\right)}=\dfrac{\left(x-3\right)\left(x-2\right)}{\left(x+1\right)\left(x-2\right)}=\dfrac{x-3}{x+1}\)
d. \(\dfrac{\left(x+y\right)^2-z^2}{2\left(x+y+z\right)}=\dfrac{\left(x+y-z\right)\left(x+y+z\right)}{2\left(x+y+z\right)}=\dfrac{x+y-z}{2}\)
CT
1
27 tháng 3 2020
Bạn hỏi lộn rồi nhưng mk sẽ giúp :))
a, mx + 2 = 0
\(\Rightarrow\) m \(\ne\) 0 để mx + 2 = 0 là phương trình bậc nhất
b, (2 - m)x + 2m = 0
\(\Leftrightarrow\) 2x - mx + 2m = 0
\(\Leftrightarrow\) 2x - m(x - 2) = 0
\(\Rightarrow\) m \(\ne\) 0 để (2 - m)x + 2m = 0 là phương trình bậc nhất
c, mx2 - x + 2m = 0
\(\Leftrightarrow\) m(x2 + 2) - x = 0
\(\Rightarrow\) m \(\ne\) 0 để mx2 - x + 2m = 0 là phương trình bậc nhất
d, (m - 1)x2 + mx - 8 = 0
\(\Leftrightarrow\) mx2 - x2 + mx - 8 = 0
\(\Leftrightarrow\) mx(x + 1) - x2 - 8 = 0
\(\Rightarrow\) m \(\ne\) 0 để (m - 1)x2 + mx - 8 = 0 là phương trình bậc nhất
Mk ko bt đúng ko nữa, dạng này mới làm lần đầu, có gì bạn thông cảm giúp mk nha
Chúc bạn học tốt!
9 tháng 12 2017
a) ĐKXĐ: \(\left\{{}\begin{matrix}3x\left(x+2\right)\ne0\\x+1\ne0\end{matrix}\right.\)
<=> \(\left\{{}\begin{matrix}3x\ne0\\x+2\ne0\\x+1\ne0\end{matrix}\right.\) <=>\(\left\{{}\begin{matrix}x\ne0\\x\ne-2\\x\ne-1\end{matrix}\right.\)
b) ĐKXĐ: \(\left\{{}\begin{matrix}x^2-x+1\ne0\\2x\ne0\end{matrix}\right.\)
<=> \(\left\{{}\begin{matrix}\left(x-1\right)^2\ne0\\x\ne0\end{matrix}\right.\) <=> \(\left\{{}\begin{matrix}x-1\ne0\\x\ne0\end{matrix}\right.\) <=> \(\left\{{}\begin{matrix}x\ne1\\x\ne0\end{matrix}\right.\)
14 tháng 10 2018
a .
a. =x3 -x2-4x2+4x+4x-4=(x-1)(x2-4x+4)=(x-1)(x-2)2
b. =x3+x2-6x2-6x+9x+9=(x+1)(x-3)2
c. =x3+x2+7x2+7x+10x+10=(x+1)(x+2)(X+5)
d. =x4+x3+x3+x2+x+1=x3(x+1)+x2(x+1)+x+1=(x+1)(x3+x2+x)=x(x+1)(x2+x+1).Ok
HA
6 tháng 4 2017
Read the following passage, choose the correct answer A, B, C or D for each question
Fishing is my favorite sport. I often fish for hours without catching anything. But it doesn’t worry me. Some fishermen are unlucky. Instead of catching fish, they catch old boots and rubbish. Iam even less lucky. I never catch anything not even an old boots. After having spent whole morning on the river, I always go home with an empty bag. My friends advise me to give up fishing. But they don’t realize one important thing. I am only interested in sitting in a boat and doing nothing at all.
1. What is the writer’s favorite sport?
A. The writer’s favorite sport is swimming. B. The writer’s favorite sport is fishing
C. The writer’s favorite sport is fish D. The writer’s favorite sport is for fishing.
2. Does he catch anything?
A. Yes, he does B. He catches many things
C. Yes, he catches a lot of things D. No, hes doesn’t
3. What do some unlucky fishermen catch?
A. He catches old boots and rubbish B. They catch old boots and many rubbish
C. They catch old boots and rubbish D. They catch many old boot and rubbish
SR
6 tháng 4 2017
Read the following passage, choose the correct answer A, B, C or D for each question
Fishing is my favorite sport. I often fish for hours without catching anything. But it doesn’t worry me. Some fishermen are unlucky. Instead of catching fish, they catch old boots and rubbish. Iam even less lucky. I never catch anything not even an old boots. After having spent whole morning on the river, I always go home with an empty bag. My friends advise me to give up fishing. But they don’t realize one important thing. I am only interested in sitting in a boat and doing nothing at all.
1. What is the writer’s favorite sport?
A. The writer’s favorite sport is swimming. B. The writer’s favorite sport is fishing
C. The writer’s favorite sport is fish D. The writer’s favorite sport is for fishing.
2. Does he catch anything?
A. Yes, he does B. He catches many things
C. Yes, he catches a lot of things D. No, hes doesn’t
3. What do some unlucky fishermen catch?
A. He catches old boots and rubbish B. They catch old boots and many rubbish
C. They catch old boots and rubbish D. They catch many old boot and rubbish
HA
6 tháng 11 2017
1. We welcome you to our city. You .......... to our city.
a- welcome b- are welcome c- have welcomed d- are welcoming
2. It was ............ an interesting book that he couldn't put it down.
a- very b- enough c- such d- so
3. I .............. detective stories but I don't anymore.
a- was used to enjoying b- was used to enjoy c- used to enjoy d- used to enjoying
4. Near the White House is an other land mark ........... the Washington Monument.
a- is which b- which called c- called d- it is called
5. I congratulate him ............ his success.
a- in b- at c- with d- on
6. ........... doesn't seem to be anyone at home.
a- It b- One c- There d- When ever
7. The sun was ......... clouds.
a- after b- in front of c- behind d- beside
8 . I’m ....with the result .
a. please b . pleasing c . pleasant d . pleased.
9 . I would .....you didn’t leave just at the moment
a . rather b . like c . ask d . advise .
10 . .......... I carry that bag for you ? Thanks .
a . Do b . Shall c . will d . would .
HA
24 tháng 3 2017
Choose the best option to complete each of the following sentences.
1. We welcome you to our city. You .......... to our city.
a- welcome b- are welcome c- have welcomed d- are welcoming
2. It was ............ an interesting book that he couldn't put it down.
a- very b- enough c- such d- so
3. I .............. detective stories but I don't anymore.
a- was used to enjoying b- was used to enjoy c- used to enjoy d- used to enjoying
4. Near the White House is an other land mark ........... the Washington Monument.
a- is which b- which called c- called d- it is called
5. I congratulate him ............ his success.
a- in b- at c- with d- on
6. ........... doesn't seem to be anyone at home.
a- It b- One c- There d- When ever
7. The sun was ......... clouds.
a- after b- in front of c- behind d- beside
8 . I’m ....with the result .
a. please b . pleasing c . pleasant d . pleased.
9 . I would .....you didn’t leave just at the moment
a . rather b . like c . ask d . advise .
10 . .......... I carry that bag for you ? Thanks .
a . Do b . Shall c . will d . would .
\(\left(a+b+c\right)^2+2\left(a+b+c\right)\left(b+c\right)+\left(b+c\right)^2\\ =\left(a+b+c+b+c\right)^2\\ =\left(a+2b+2c\right)^2\)