thì nước sâu quá

BẠN TICK CHO MIK NHA,CẢM ƠN BẠN RẤT NHIỀU

chẳng thấy cái sit gì

II) 1.get - got

2. play - played

3. watch - watched

4. finish - finished

5.speak - spoke

6. see - să

7. invent - invented

8. can - could

III) 1. for

2. on

3. of

4 .in

IV) 1. listening

2. got

3. clean

4. to finish

V) 1. What time đi he get up yesterday morning ?

2. How often do you brush your teeth ?

3. Why did your mother go to bed early ?

4. How heavy are you ?

VI) 1. A

2. C

3. B

4. C

5. C

6. A

7. A

8. C

tham khảo câu b ở http://olm.vn/hoi-dap/question/178348.html

nếu có sai thì cho mk sorry nha !

Ta có : -x(x-2)+6 = 0

=> -x²+ 2x +6 = 0

=> - (x² - 2x -6)=0

=> - ( x² -x -x -6) = 0

=> -[x(x-1)-(x-1)-7] = 0

=> -[(x-1).(x-1)-7] = 0

=> -(x-1)² + 7 = 0

=> -(x-1)² = -7

=> (x-1)² = 7

=> \(\left[{}\begin{matrix}x-1=\sqrt{7}\\x-1=-\sqrt{7}\end{matrix}\right.\)

=> \(\left[{}\begin{matrix}x=\sqrt{7}+1\\x=-\sqrt{7}+1\end{matrix}\right.\)

Vậy x = \(\sqrt{7}+1\) ; x = \(-\sqrt{7}+1\) là nghiệm của - x(x-2)+6

Ta có :

\(\dfrac{x+5}{25}+\dfrac{x+6}{24}+\dfrac{x+7}{23}=-3\)

=> \(\left(x+5\right).\dfrac{1}{25}+\left(x+5+1\right).\dfrac{1}{24}+\left(x+5+2\right).\dfrac{1}{23}=-3\)

=>\(\left(x+5\right).\dfrac{1}{25}+\left(x+5\right).\dfrac{1}{24}+\dfrac{1}{24}+\left(x+5\right).\dfrac{1}{23}+2.\dfrac{1}{23}\)= -3

=> (x + 5).\(\left(\dfrac{1}{25}+\dfrac{1}{24}+\dfrac{1}{23}\right)\) + \(\dfrac{1}{24}+\dfrac{2}{23}\) = -3

=> (x + 5). \(\dfrac{1727}{13800}\) + \(\dfrac{71}{552}\) = -3

=> (x + 5). \(\dfrac{1727}{13800}\) = -3 - \(\dfrac{71}{552}\)

=> (x + 5). \(\dfrac{1727}{13800}\) = \(\dfrac{-1727}{552}\)

=> x + 5 = -25

=> x = -25-5

=> x = -30

Vậy x = -30

Ta có :

xy + 2x - y = 5

=> x.(y+2)-y-2 = 3

=> x.(y+2)-(y+2) = 3

=> (x-1).(y+2) = 3

=> x-1 \(\in\) Ư(3)

=> x-1 \(\in\) {-1;-3;1;3}

*) Với x-1 = -1

=> x = 0

Khi đó : y+2 = -3

=> y = -5

*) Với x-1 = -3

=> x = -2

Khi đó : y+2 = -1

=> y = -3

*) Với x-1 = 1

=> x = 2

Khi đó : y+2 = 3

=> y = 1

*) Với x-1 = 3

=> x = 4

Khi đó : y+2 = 1

=> y = -1

Vậy ta được các cặp (x;y) thoả mãn là :

(0;-5);(-2;-3);(2;1);(4;-1)

Ta có:

A = \(\dfrac{101+100+99+98+...+1}{101-100+99-98+...+3-2+1}\)

= \(\dfrac{101+\left(100+1\right)+\left(99+2\right)+...+\left(51+50\right)}{\left(101-100\right)+\left(99-98\right)+...+\left(3-2\right)+1}\)

= \(\dfrac{101+101+101+...+101}{1+1+1+...+1}\) (51 số 101 và 51 số 1)

= \(\dfrac{101.51}{51}\)

= 101

Vậy A = 101

Ta có :

A = \(\dfrac{-5}{7}.\dfrac{2}{11}+\dfrac{-5}{7}.\dfrac{9}{11}+1\dfrac{5}{7}\)

= \(\dfrac{5}{7}.\dfrac{-2}{11}-\dfrac{5}{7}.\dfrac{9}{11}+\dfrac{5}{7}+1\)

= \(\left(\dfrac{5}{7}.\dfrac{-2}{11}-\dfrac{5}{7}.\dfrac{9}{11}+\dfrac{5}{7}\right)+1\)

= \(\dfrac{5}{7}.\left(\dfrac{-2}{11}-\dfrac{9}{11}+1\right)+1\)

= \(\dfrac{5}{7}.0+1\)

= 1

B = \(0,7.2\dfrac{2}{3}.20.0,375.\dfrac{5}{28}\)

= \(\dfrac{7}{10}.\dfrac{8}{3}.20.\dfrac{3}{8}.\dfrac{5}{28}\)

= \(\left(\dfrac{7}{10}.20\right).\left(\dfrac{8}{3}.\dfrac{3}{8}\right).\dfrac{5}{28}\)

= 14.1.\(\dfrac{5}{28}\)

= \(\dfrac{5}{2}\)

Vậy A = 1

B = \(\dfrac{5}{2}\)