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11 tháng 10 2021

1: Ta có: \(\left(x^3-4x^2\right)-\left(x-4\right)=0\)

\(\Leftrightarrow\left(x-4\right)\left(x+1\right)\left(x-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=1\\x=-1\end{matrix}\right.\)

11 tháng 10 2021

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Ta có: \(Q=\dfrac{4}{P}\)

\(=4:\dfrac{2x^2}{x-3}\)

\(=4\cdot\dfrac{x-3}{2x^2}\)

\(=\dfrac{2x-6}{x^2}\)

Ta có: \(Q-1=\dfrac{2x-6-x^2}{x^2}=\dfrac{-\left(x^2+2x+6\right)}{x^2}\)

\(=\dfrac{-\left(x^2+2x+1\right)-5}{x^2}\)

\(=\dfrac{-\left(x+1\right)^2-5}{x^2}< 0\)

=> Q<1

5 tháng 5 2023

Câu 2:

\(A\left(x\right)=x^2+3x+1\)

\(B\left(x\right)=2x^2-2x-3\)

a) Tính A(x) là sao em?

b) \(A\left(x\right)+B\left(x\right)=\left(x^2+3x+1\right)+\left(2x^2-2x-3\right)\)

\(=x^2+3x+1+2x^2-2x-3\)

\(=\left(x^2+2x^2\right)+\left(3x-2x\right)+\left(1-3\right)\)

\(=3x^2+x-2\)

5 tháng 5 2023

Câu 1:

\(M\left(x\right)=x^3+3x-2x-x^3+2\)

\(=\left(x^3-x^3\right)+\left(3x-2x\right)+2\)

\(=x+2\)

Bậc của M(x) là 1

28 tháng 3 2022

will bake

will take

will stay

will be

28 tháng 3 2022

Lẹ vậy tròi!

31 tháng 8 2021

a, ĐK: \(x\ge2\)

\(\sqrt{2x+1}-\sqrt{x-2}=x+3\)

\(\Leftrightarrow\dfrac{x+3}{\sqrt{2x+1}+\sqrt{x-2}}=x+3\)

\(\Leftrightarrow\left(x+3\right)\left(\dfrac{1}{\sqrt{2x+1}+\sqrt{x-2}}-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-3\left(l\right)\\\sqrt{2x+1}+\sqrt{x-2}=1\left(vn\right)\end{matrix}\right.\)

Phương trình vô nghiệm.

 

31 tháng 8 2021

b, ĐK: \(x\ge-1\)

\(\sqrt{x+3}+2x\sqrt{x+1}=2x+\sqrt{x^2+4x+3}\)

\(\Leftrightarrow\sqrt{x+3}+2x\sqrt{x+1}=2x+\sqrt{\left(x+3\right)\left(x+1\right)}\)

\(\Leftrightarrow-\sqrt{x+3}\left(\sqrt{x+1}-1\right)+2x\left(\sqrt{x+1}-1\right)=0\)

\(\Leftrightarrow\left(2x-\sqrt{x+3}\right)\left(\sqrt{x+1}-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}\sqrt{x+3}=2x\\\sqrt{x+1}=1\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x\ge0\\x+3=4x^2\end{matrix}\right.\\x=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=1\left(tm\right)\\x=0\left(tm\right)\end{matrix}\right.\)

5 tháng 10 2021

\(\left(4x-5\right)\left(2x+30\right)-4\left(x+2\right)\left(2x-1\right)+\left(10x+7\right)\)

\(=8x^2+110x-150-8x^2-12x+8+10x+7\)

\(=108x-135\)

5 tháng 10 2021

$(4x-5)(2x+30)-4(x+2)(2x-1)+(10x+7)\\=4x(2x+30)-5(2x+30)-4[x(2x-1)+2(2x-1)]+10x+7\\=8x^2+120x-10x-150-4[2x^2-x+4x-2]+10x+7\\=8x^2+120x-143-4[2x^2+3x-2]\\=8x^2+120x-143-8x^2-12x+8\\=108x-135$

28 tháng 2 2022
28 tháng 2 2022

\(\dfrac{1}{2}-\dfrac{1}{3}=\dfrac{1}{6}\) mà

ai giúp với1. Tom played the game ………………………………. ( excellent2. I hope that we will have a good ………………….. ( cooperate)3. This bookshop offers a wide …………………….. of book in foreign languages ( select)4. The house is small, but it is very …………………. ( comfort )5. Canadian Prime Minister Justin Trudeau looked ………………………… impressed by the Vovinam ( deep) 6. She has never …………………… anything like it (...
Đọc tiếp

ai giúp với

1. Tom played the game ………………………………. ( excellent

2. I hope that we will have a good ………………….. ( cooperate)

3. This bookshop offers a wide …………………….. of book in foreign languages ( select)

4. The house is small, but it is very …………………. ( comfort )

5. Canadian Prime Minister Justin Trudeau looked ………………………… impressed by the Vovinam ( deep) 

6. She has never …………………… anything like it ( tasty)

7. I don’t know how to cook, so the meat was dry and ………………………… ( taste)

8. I read that book many times because I found it ………………………. ( interest )

9. They do a really …………………… chicken and mushroom soup ( taste )

10. The internet is a fast and ……………………. Way for us to communicate with friends ( convenience)

11. Rice cooked in clay pot is one of the ……………………… in this restaurant ( special) 

12. When would be a ………………………… time for you to meet me? ( convenience)

13. His company exports many farm ……………………… (production)

14. In this resort, you can enjoy all the comfort and………………………. Of modern tourism ( convenient)

15. The stores in mall will offer a wide ………………………… of products ( select )

16. After ……………………………., they decided to accept our offer ( discuss)

17. Rice is Vietnam’s main ……………………………. ( produce )

18. I don’t like the ……………………. Of olives ( tasty)

19. The food was nice, but the ……………….. wasn’t good. ( serve)

20. We grew up in the same ………………………… ( neighbor)

21. The hotel is ………………… situated close to the beach ( convenience)

1
23 tháng 12 2021

giúp với ặ

 

12 tháng 2 2016

<=>|2x+4|=2|x+2|

=>|x-3|=2|x+2|

=>x=-7 hoặc \(-\frac{1}{3}\)

11 tháng 2 2016

vậy thì bạn giúp với