a/

(3x-1)²+(5-x)(3x-1)=0

\(\Leftrightarrow\)(3x-1)(3x-1+5-x)=0

​\(\Leftrightarrow\)​(3x-1)(2x+4)=0

\(\Leftrightarrow\)\(\left[\begin{matrix}3x-1=0\\2x+4=0\end{matrix}\right.\)\(\Leftrightarrow\)\(\left[\begin{matrix}x=\frac{1}{3}\\x=-2\end{matrix}\right.\)

vậy x=1/3, x=-2

b/(x+3)(2-3x)=x²+6x+9

d/

4x²-12x+5=0 \(\Leftrightarrow\) 4x²-2x-10x+5=0

\(\Leftrightarrow\)(4x²-2x)-(10x-5)=0 \(\Leftrightarrow\) 2x(2x-1)-5(2x-1)=0

\(\Leftrightarrow\) (2x-1)(2x-5)=0

\(\Leftrightarrow\)\(\left[\begin{matrix}2x-1=0\\2x-5=0\end{matrix}\right.\)\(\Leftrightarrow\)\(\left[\begin{matrix}x=\frac{1}{2}\\x=\frac{5}{2}\end{matrix}\right.\)

vậy x=\(\frac{1}{2}\),x=\(\frac{5}{2}\)

c/

x²-3x+2=0 \(\Leftrightarrow\) x² -2x-x+2=0

\(\Leftrightarrow\) (x² -2x)-(x-2)=0 \(\Leftrightarrow x\left(x-2\right)-\left(x-2\right)=0\)

\(\Leftrightarrow\) (x-2)(x-1)=0

\(\Leftrightarrow\) \(\left[\begin{matrix}x-2=0\\x-1=0\end{matrix}\right.\)\(\Leftrightarrow\)\(\left[\begin{matrix}x=2\\x=1\end{matrix}\right.\)

vậy x=2,x=1

b/

x³+x²+x+1=0 \(\Leftrightarrow\)(x³+x²)+(x+1)=0

\(\Leftrightarrow\) x²(x+1)+(x+1)=0

\(\Leftrightarrow\) (x+1)(x²+1)=0

\(\Leftrightarrow\) \(\left[\begin{matrix}x+1=0\\x^2+1=0\end{matrix}\right.\) \(\Leftrightarrow\) \(\left[\begin{matrix}x=-1\\x^2=-1\left[vô\right]lý\end{matrix}\right.\)

vậy x=-1

a/

x³ +1=x(x+1) \(\Leftrightarrow\) (x+1)(x² -x+1)=x(x+1)

\(\Leftrightarrow\) (x+1)(x² -x+1)- x(x+1)=0

\(\Leftrightarrow\)(x+1)(x² -x+1 -x)=0

\(\Leftrightarrow\) (x+1)(x² -2x+1)=0 \(\Leftrightarrow\)(x+1)(x -1)²=0

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

vậy x=-1, x=1

(1) lan didn't come to school, so does Mai

(2) lan didn't come to school, Mai does too

(3) lan and mai didn't come to school

- qủa khô không nẻ: quả chò, quả thìa là, quả lạc , quả cải, .....

-quả mọng: quả cà chua, quả chanh, quả đu đủ, quả chuối, quả hồng, quả nho,....

Insulin là một hoóc môn có tác dụng làm giảm đường máu do tế bào beta tụy tiết ra do đó nó được sử dụng làm thuốc trị bệnh tiểu đường

1. Where ____do_______you (live)_____live_______? I (live)______live________in Hai Duong town.

2. What is he (do) ______doing___________now? He (water)___is watering______________flowers in the garden.

3. What ______does_________she (do)______do_______? She (be)_____is_________a teacher.

4. Where _____are____________you (be)come from?

5. At the moment, my sisters (play)___is playing_________volleyball and my brother (play) ____is playing____________soccer.

6. it is 9.00; my family (watch)_______are watching____________TV.

7. In the summer, I usually (go)______go________to the park with my friends, and in the spring, we (have) _____have________Tet Holiday; I (be)__am______happy because I always (visit) _____visit_________my granparents.

8. _______does_____your father (go)____go_________to work by bus?

9. How _____does______your sister (go)__go_________to school?

10. What time ________do_____they (get up)_____get up____________?

11. What _____do_______they (do)____do____________in the winter?

12. Today, we (have)_______have_______English class.

13. Her favourite subject (be)______is____________English.

14. Now, my brother (like)______likes___________eating bananas.

15. Look! A man (call)________is calling_________you.

16. Keep silent ! I (listen )_______am listening_____________to the radio.

17. ____are__________ you (play)_____playing____________badminton now?

18. Everyday, my father (get up)_____gets up__________at 5.00 a.m.

19. Every morning, I (watch)______watch___________tv at 10.00.

20. Everyday, I (go) _____go_____to school by bike.

21. Every morning, my father (have) _____has_________a cup of coffe.

22. At the moment, I(read)_____am reading__________a book and my brother (watch)___is watching____ TV.

23. Hoa (live)______lives__________in Hanoi, and Ha (live)___lives_____________in HCM City.

24. Hung and his friend (play)_____are playing__________badminton at the present.

25. They usually (get up)________get up___________at 6. oo in the morning.

26. Ha never (go)___goes________fishing in the winter but she always (do)__does______ it in the summer.

27. My teacher (tell)_______is telling___________Hoa about Math at the moment.

28. There (be)_______are_____________ animals in the circus.

29. ____does___________he (watch)_____watch_________TV at 7.00 every morning?

30. What ______does_______she (do ) _______do__________at 7.00 am?

31. How old ___is______she (be)?

32. How ____is_______she (be)?

33. My children (Go)________goes________to school by bike.

34. We (go)_______go________to supermarket to buy some food.

35. Mr. Hien (go)_____goes___________on business to Hanoi every month.

36. Ha (like)______likes________coffee very much, but I (not like)__don't like____________it.

37. She (like )____likes____________Tea, but she (not like)___doesn't like_________________coffee.

38. I (love)_____love__________ cats, but I (not love)___don't love_______________dogs.

39. Everyday, I (go)______go________to school on foot.

40. Who you _____waiting____________(wait) for Nam?

- No, I ____am waiting_ ______ (wait) for Mr. Hai.

41. My sister (get)________gets______ dressed and (brush)___brushes____________her teeth herself at 6.30 everyday.

42. Mrs. Smith (not live)______doesn't live_________in downtown. She (rent)_____rents___________in an appartment in the suburb.

43. How __does_______your children (go)______go___________to school everyday?

44. It's 9 o'clock in the morning. Lien (be)___is_____in her room. She (listen) __is listening_____________to music.

45. We______are playing_________________(play) soccer in the yard now.

46. My father (go)___goes________ to work by bike. Sometimes he(walk)_walks_____________.

47. ___do______You (live)____live____near a market? _ It (be)__is__________noisy?

48. Now I (do)_am doing_________the cooking while Hoa (listen)__is listening___________to music.

49. At the moment, Nam and his friends (go)___are going____________shopping at the mall.

50. In the autumn, I rarely (go)____go_________sailing and (go)_go_________to school.