Trả lời ; 

1 + 1 = 2

#hok tút#

1 has changed

2 are driving

3 were made

4 went - saw

5 finish

6 have been

7 weren't

8 will write

9 doing

10 to work

11 will clean

12 tastes - are

13 has become

14 went

15 is learning

16 won't be

17 is cut

18 eats

19 stewing

20 to drink

21 is organised

22 built

23 were made

14 was set

25 haven't done

26 is speaking

27 are spoken

a) \(\left(2x+1\right)^2-4\left(x+2\right)^2=9\\ \Rightarrow\left(2x+1\right)^2-\left[2\left(x+2\right)\right]^2=9\\ \Rightarrow\left(2x+1-2x-4\right)\left(2x+1+2x+4\right)=9\\ \Rightarrow-3\left(4x+5\right)=9\\ \Rightarrow-12x-15=9\\ \Rightarrow x=-2\)

b) \(\left(x+3\right)^2-\left(x-4\right)\left(x+8\right)=1\\ \Rightarrow x^2+6x+9-\left(x^2+4x-32\right)=1\\ \Rightarrow x^2+6x+9-x^2-4x+32=1\\ \Rightarrow2x=-40\\ \Rightarrow x=-20\)

\(a,\Rightarrow4x^2+4x+1-4x^2-16x-16=9\\ \Rightarrow-12x=24\Rightarrow x=-2\\ b,\Rightarrow x^2+6x+9-x^2-4x+32=1\\ \Rightarrow2x=-40\Rightarrow x=-20\\ c,\Rightarrow3x^2+12x+12+4x^2-4x+1-7x^2+63=36\\ \Rightarrow8x=-40\Rightarrow x=-5\\ d,\Rightarrow x^3-27+4x-x^3=1\\ \Rightarrow4x=28\Rightarrow x=7\\ e,\Rightarrow x^3+3x^2+3x+1-x^3+3x^2-3x+1-6x^2+12x-6=-19\\ \Rightarrow12x=-15\Rightarrow x=-\dfrac{5}{4}\)

=2768 dư 1

124565 : 45 = 24913/9 = 2768,1111111

2768(R=5)

c. \(\left|\dfrac{8}{4}-\left|x-\dfrac{1}{4}\right|\right|-\dfrac{1}{2}=\dfrac{3}{4}\)

\(\Rightarrow\left[{}\begin{matrix}\left|\dfrac{8}{4}-x+\dfrac{1}{4}\right|-\dfrac{1}{2}=\dfrac{3}{4}\\\left|\dfrac{8}{4}+x-\dfrac{1}{4}\right|-\dfrac{1}{2}=\dfrac{3}{4}\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}\left|\dfrac{9}{4}-x\right|-\dfrac{1}{2}=\dfrac{3}{4}\\\left|\dfrac{7}{4}+x\right|-\dfrac{1}{2}=\dfrac{3}{4}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}\left[{}\begin{matrix}\dfrac{9}{4}-x-\dfrac{1}{2}=\dfrac{3}{4}\\x=\dfrac{9}{4}-\dfrac{1}{2}=\dfrac{3}{4}\end{matrix}\right.\\\left[{}\begin{matrix}\dfrac{7}{4}+x-\dfrac{1}{2}=\dfrac{3}{4}\\-\dfrac{7}{4}-x-\dfrac{1}{2}=\dfrac{3}{4}\end{matrix}\right.\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}\left[{}\begin{matrix}x=1\\x=\dfrac{7}{2}\end{matrix}\right.\\\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=-3\end{matrix}\right.\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=1\\x=\dfrac{7}{2}\\x=-3\end{matrix}\right.\) 

Ở nơi x=9/4-1/2 là x-9/4-1/2 nha

a. -1,5 + 2x = 2,5

<=> 2x = 2,5 + 1,5

<=> 2x = 4

<=> x = 2

b. \(\dfrac{3}{2}\left(x+5\right)-\dfrac{1}{2}=\dfrac{4}{3}\)

<=> \(\dfrac{3}{2}x+\dfrac{15}{2}-\dfrac{1}{2}=\dfrac{4}{3}\)

<=> \(\dfrac{9x}{6}+\dfrac{45}{6}-\dfrac{3}{6}=\dfrac{8}{6}\)

<=> 9x + 45 - 3 = 8

<=> 9x = 8 + 3 - 45

<=> 9x = -34

<=> x = \(\dfrac{-34}{9}\)

a/ Tam giác AMN cân tại A (gt). \(\Rightarrow\) \(\widehat{AMN}=\widehat{ANM};AM=AN.\)

Xét tam giác AMB và tam giác ANC có:

+ AM = AN (cmt).

+ \(\widehat{AMB}=\widehat{ANC}\left(\widehat{AMN}=\widehat{ANM}\right).\)

+ MB = NC (gt).

\(\Rightarrow\) Tam giác AMB = Tam giác ANC (c - g - c).

\(\Rightarrow\) AB = AC (cặp cạnh tương ứng).

Xét tam giác ABC có: AB = AC (cmt).

\(\Rightarrow\) Tam giác ABC cân tại A.

b/ Tam giác ABC cân tại A (cmt) \(\Rightarrow\) \(\widehat{ABC}=\widehat{ACB}.\)

Mà \(\widehat{ABC}=\widehat{MBH;}\widehat{ACB}=\widehat{NCK}\text{​​}\) (đối đỉnh).

\(\Rightarrow\) \(\widehat{MBH}=\widehat{NCK}.\)

Xét tam giác MBH và tam giác NCK \(\left(\widehat{BHM}=\widehat{CKN}=90^o\right)\)có:

+ MB = NC (gt).

+ \(\widehat{MBH}=\widehat{NCK}\left(cmt\right).\)

\(\Rightarrow\) Tam giác MBH = Tam giác NCK (cạnh huyền - góc nhọn).

c/ Tam giác MBH = Tam giác NCK (cmt).

\(\Rightarrow\) \(\widehat{BMH}=\widehat{CNK}\) (cặp góc tương ứng).

Xét tam giác OMN có: \(\widehat{NMO}=\widehat{MNO}\) (do \(\widehat{BMH}=\widehat{CNK}\)).

\(\Rightarrow\) Tam giác OMN tại O.

2 dreamed/dreamt

3 were taking

4 was

5 were 

6 were travelling

7 was

8 were sitting

9 were drinking

10 were dancing

11 was playing

12 had

13 arrived

14 was waiting

15 stayed

16 were beating

17 were singing

18 were dancing

19 was getting

20 heard

21 was

22 was

mm spam:))

Thôi coi như ko thấy j đi srrrrr

a: \(x^2-9y^2=\left(x-3y\right)\left(x+3y\right)\)

c: \(\left(x+5\right)^2-16=\left(x+1\right)\left(x+9\right)\)

e: \(\left(2x+3\right)^2-\left(x-7\right)^2\)

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

\(=\left(3x-4\right)\left(x+10\right)\)