(-1)+3+(-5)+7+....+x = 600

<=> [(-1) + 3] + [(-5) + 7] .... + [(-x) - 2) + x] = 600 

Ta có : 2 + 2 + 2 +.....+ 2 = 600 

<=> 1 + 1 + 1 +.....+ 1 = 300 

Số dấu ngoặc[ ] là :\(\frac{x-3}{4}+1\)

=>\(\frac{x-3}{4}+1=300\)

<=>\(\frac{x-3}{4}=299\)

<=> x - 3 = 299 . 4 = 1199

Vậy x = 1199

a)đặt là A

r xét 3A=3².3³....3¹⁰⁰

    -        A=3¹.3².3³.....3⁹⁹

2A=3¹⁰⁰-3

A=(3¹⁰⁰-3)/2

7x - 2x = 6² + 44 : 11

5x = 6² + 4

5x = 40

x = 40 : 5

x = 8

Vậy x = 8

\(7x-2x=6^2+44:11\)

\(\Leftrightarrow5x=6^2+4\)

\(\Leftrightarrow5x=36+4\)

\(\Leftrightarrow5x=40\)

ko có bài văn hả bn,. ko có sao trả lời

cứ suy đoán thôi

\(A=4+2^3+2^3+2^4+.....+2^{20}\)

\(\Leftrightarrow2A=2.\left(4+2^3+2^3+2^4+...+2^{20}\right)\)

\(=8+2^3+2^4+....+2^{20}+2^{21}\)

\(\Leftrightarrow2A-A=2^{21}\)

\(\Rightarrow\)ĐÓ LÀ LŨY THỪA CỦA 2

4.chia động từ thường

1 I (listen)listen to music every day

2. They (go)go to  school every day

3. We (get )get up at 5 every morning

4. You (live)live in a  big city

5. Nga and Lan(brush)brush their teeth

6. Nam and Ba (wash)wash their face

7. I(have)have Breakfast every moring

8. Na (have)has breakfast at 6 o'clock

9. Every morning Ba (get)gets up

10. He (brush) brushes his teeth

11. Then he (wash)washes  his face

12. Next he (have)has breakfast

13. Finally he(go)goes to school

14. Nga(do)does homework every day

15. Linh (watch)watches television at night

16. She often (miss) misses her parents

17.  He always(study)studies English

18. Loan(have)has dinner at 7 pm

19.  I (have)have dinner at 6 pm

20. They (do )do homework at 2pm

21. You(watch)watch  movies  at 8.30

22. We (study)study English on mondays

23.  Hoa(have)has English on Tuesday

24. Lan (open)opens the door

25. Hoa(close) closes the window

26. The teacher(come)comes in

27. The students(stand) stand up

28. They(sit) sit down

29. My father(live)lives in a big city

30. Your friend(go)goes  home at 4pm

~~~~~~~~~~Study well ~~~~~~~~~~~~~~

1: i listen to music every day

2: they goes to school every day.

3: we gets up at 5 every day.

4. You lives in a  big city

5. Nga and Lan brushes their teeth

6. Nam and Ba washes their face

7. I have Breakfast every moring

8. Na has breakfast at 6 o'clock

9. Every morning Ba gets up

10. He brushes his teeth

11. Then he washes his face

12. Next he has breakfast

13. Finally he goes to school

14. Nga does homework every day

15. Linh watches television at night

16. She often miss her parents

17.  He always study English

18. Loan has dinner at 7 pm

19.  I have dinner at 6 pm

20. They do homework at 2pm

21. You watchs movies  at 8.30

22. We will study English on mondays

23.  Hoa will have English on Tuesday

24. Lan opens the door

25. Hoa is close the window

26. The teacher comes in

27. The students stand up

28. They sit down

29. My father live in a big city

30. Your friend go home at 4pm

x.(x+1)=2+6+8+4

x.(x+1)=20

x.(x+1)=4.5

Vậy x là 4

\(x.\left(x+1\right)=2+6+4+8\)

\(\Leftrightarrow x.\left(x+1\right)=\left(2+8\right)+\left(6+4\right)\)

\(\Leftrightarrow x.\left(x+1\right)=10+10\)

\(\Leftrightarrow x.\left(x+1\right)=20\)

\(\Leftrightarrow x.\left(x+1\right)=4.5\)

\(\Leftrightarrow x+1=5\)

\(\Leftrightarrow x=4\)

322 nha bn

Học tốt

23.14=322

Chúc học tốt 

1  Is Mr Nam a teacher?

My answer:

Is Mr Nam a teacher?

Học tốt!!

#diemconglinh#