a: Ta có: \(3\left(x-2\right)^2+\left(x-1\right)^3-x^3=-7\)

\(\Leftrightarrow3x^2-12x+12+x^3-3x^2+3x-1-x^3=-7\)

\(\Leftrightarrow-9x=-18\)

hay x=2

b: ta có: \(\left(x+2\right)^3-x\left(x-1\right)\left(x+1\right)=6x^2-5x+3\)

\(\Leftrightarrow x^3+6x^2+12x+8-x^3+x-6x^2+5x-3=0\)

\(\Leftrightarrow17x=-5\)

hay \(x=-\dfrac{5}{17}\)

c: Ta có: \(\left(2x-1\right)^3+12\left(x-1\right)\left(x+1\right)=14x-13\)

\(\Leftrightarrow8x^3-12x^2+6x-1+12x^2-12-14x+13=0\)

\(\Leftrightarrow8x^3-8x=0\)

\(\Leftrightarrow8x\left(x-1\right)\left(x+1\right)=0\)

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

a) \(3\left(x-2\right)^2+\left(x-1\right)^3-x^3=-7\)

\(\Rightarrow3x^2-12x+12+x^3-3x^2+3x-1-x^3=-7\)

\(\Rightarrow-9x=-18\)

\(\Rightarrow x=2\)

b) \(\left(x+2\right)^3-x\left(x-1\right)\left(x+1\right)=6x^2-5x+3\)

\(\Rightarrow x^3+6x^2+12x+8-x^3+x=6x^2-5x+3\)

\(\Rightarrow18x=-5\)

\(\Rightarrow x=-\dfrac{5}{18}\)

c) \(\left(2x-1\right)^3+12\left(x-1\right)\left(x+1\right)=14x-13\)

\(\Rightarrow8x^3-12x^2+6x-1+12x^2-12=14x-13\)

\(\Rightarrow8x^3-8x=0\)

\(\Rightarrow8x\left(x-1\right)\left(x+1\right)=0\)

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

2. will be waiting

3. are going to => will

những câu còn lại bạn Xuân Mai làm đúng rồi em nhé!

POP POP đây bạn giúp mình nha 

(っ◔◡◔)っ ♥ Aurora ♥ giúp mình với 
mình sắp đi hc r

12 What do you often do after school?

13 What is he doing now?

14 Where are you often have dinner?

15 What is Lan going to buy

16 Where are they going to stay?

17 Why do you like learning English?

18 How many pens does she want>

19 What does Nam have for for lunch

20 How many books does Ha have in the bags?

12. What do you often do after school?

13. What is he doing now?

14. Where do you often have dinner? 

15. What is Lan going to buy?
16. Where are they going to stay?

 17. Why do you like learning English?
18. How many pens does she want?

19. What does Nam have for lunch? 

20. How many books does Ha have in the bags? 

Câu nào bạn ơi

hình thì đăng 1 câu thôi:)

Giúp ik

xét tam giác amb và tam giác amc 

am là cạnh chung 

mb =mc (am là trung tuyến )

ab =ac tam giác abc cân 

tam giác amb =amc (ccc)

dpcm

b)ta có tam giác amb = tam giác amc 

bam = cam ( 2 góc tương úng)

am là tia phân giác của bac

C)xét tam giấcpm và tam  giác aqm 

am là cạnh chung 

ap = aq 

pam = qam 

tam giác apm = tam giác aqm

pm = qm ( 2 cạnh tương ứng )

xét tam giác apm và tam giác aqm 

pm =qm ( cmt ) 

pb = qc 

bm = cm 

tam giác apm = tam giác aqm 

mp = mq 

dpcm

làm mõi bài 1 thôi nhé

\(2^{x-3}-3.2^x=-92\)

\(\Rightarrow2^x:2^3-3.2^x=-92\)

\(\Rightarrow2^x.\frac{1}{2^3}-3.2^x=-92\)

\(\Rightarrow2^x.\left(\frac{1}{2^3}-3\right)=-92\)

\(\Rightarrow2^x.\frac{-23}{8}=-92\)

\(\Rightarrow2^x=2^5\)

\(\Rightarrow x=5\)