a) `3x+m(y-1)=2`

`<=> (y-1)m=2-3x`

`<=>y-1=0` và `2-3x=0`

`<=>y=1` và `3x=2`

`<=>y=1` và `x=2/3` 

=>  Đường thẳng luôn đi qua điểm `(2/3;1)` cố định với mọi m 

b) `mx+(m-2)y=m`

`<=>mx+my-2y=m`

`<=>mx+my-m=2y`

`<=>m(x+y-1)=2y`

`<=>x+y-1=0` và `2y=0`

`<=>x+y=1` và `y=0`

`<=>x=1` và `y=0` 

=> Đường thẳng luôn đi qua điểm `(1;0)` cố định với mọi m 

Vì a>b

nên 4a>4b

=>4a+7>4b+7

mà 4b+7>4b+5

nên 4a+7>4b+5

Vì: \(a>b\) nên nhân a,b với \(4\), ta có:

\(4a>4b\)

Biết: \(7>5\)

\(\rightarrow4a+7>7b+5\left(đpcm\right)\)

1. He would have solved the puzzle had he watched the news.
2. If I had had a mobile, I could have phoned you.
3. Were I to ask you to lend me your dictionary, would you do it?
4. The money will only be paid should a new contract be signed.
5. I’d appreciate it if you would reply at your earliest convenience.
6. If only I had known you earlier.
7. But for your absent-mindedness then, the soup would have tasted excellent.
8. They would have paid less if they had booked the tickets yesterday.
9.If you like, you can stay for two days.
10.If the parents were to buy the cat, their children would be very happy.

As long as you follow the instructions carefully, there won't be any problems.

please giúp nhanh với mọi người ơi

51 enthusiastically (đằng sau có prepare là động từ nên cần trạng từ để bổ nghĩa)

52 adventurous (đằng sau là outdoor activities là danh từ nên dùng tính từ để bổ nghĩa)

53 to modify (decide to V)

54 skillfully (đằng sau là động từ craft nên dùng trạng từ để bổ nghĩa)

55 entertainingly

56. Many tourists visit beaches to relax and enjoy the sun.

→ Beaches ............are visited by many tourists to relax and enjoy the sun....................................................................................................................................

57. “Are you planning to book a guided tour of the national park?” she asked.

→ She asked..........if I was planning to book a guided tour of the national park...................................................................................................................................

58. If you explore new cultures, you'll broaden your horizons.

→ Exploring...........new cultures, you will broaden your horizons...................................................................................................................................

59. They stayed in a cozy cabin in the mountains last summer.

→ They...spent last summer staying in a cozy cabin in the mountains....................................................................................................................................................

60. Despite the rainy weather, they hiked to the waterfall.

→ Although........the weather was rainy, they hiked to the waterfall.......................................................................................................................................

• Beaches are visited by many tourists to relax and enjoy the sun.

• She asked if I was planning to book a guided tour of the national park.

• Exploring new cultures will broaden your horizons.

• They spent last summer staying in a cozy cabin in the mountains.

• Although the weather was rainy, they hiked to the waterfall.

56. Many tourists visit beaches to relax and enjoy the sun.

→ Beaches ............are visited by many tourists to relax and enjoy the sun....................................................................................................................................

57. “Are you planning to book a guided tour of the national park?” she asked.

→ She asked..........if I was planning to book a guided tour of the national park...................................................................................................................................

58. If you explore new cultures, you'll broaden your horizons.

→ Exploring...........new cultures, you will broaden your horizons...................................................................................................................................

59. They stayed in a cozy cabin in the mountains last summer.

→ They...spent last summer staying in a cozy cabin in the mountains....................................................................................................................................................

60. Despite the rainy weather, they hiked to the waterfall.

→ Although........the weather was rainy, they hiked to the waterfall.......................................................................................................................................

51. enthusiastically

52. adventurous

53. to modify

54. skillfully

55. entertainingly

51 enthusiastically (đằng sau có prepare là động từ nên cần trạng từ để bổ nghĩa)

52 adventurous (đằng sau là outdoor activities là danh từ nên dùng tính từ để bổ nghĩa)

53 to modify (decide to V)

54 skillfully (đằng sau là động từ craft nên dùng trạng từ để bổ nghĩa)

55 entertainingly

`{(-6x + 3y = -3),(-10x - y = -5 - 3xy):}`

`<=> {(-2x + y = -1),(-10x - y = -5 - 3xy):}`

`<=> {(y =2x -1),(-10x - y = -5 - 3xy):}`

`<=> {(y =2x -1),(-10x - (2x -1) = -5 - 3x(2x -1)(1)):}`

Từ (1) `<=> -10x - 2x + 1 = -5x - 6x^2 + 3x`

`<=> 6x^2 - 3x + 5 -10x - 2x + 1 = 0 `

`<=> 6x^2 - 15x + 6 = 0`

`<=> 2x^2 - 5x + 2 = 0`

`<=> (2x^2 - 4x) - (x - 2) = 0`

`<=> 2x(x-2) - (x-2) = 0`

`<=> (2x - 1)(x-2) = 0`

<=> \(\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=2\end{matrix}\right.\)

Hệ phương trình <=> \(\left\{{}\begin{matrix}\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=2\end{matrix}\right.\\y=2x-1\end{matrix}\right.\)

<=> \(\left[{}\begin{matrix}\left\{{}\begin{matrix}x=\dfrac{1}{2}\\y=0\end{matrix}\right.\\\left\{{}\begin{matrix}x=2\\y=3\end{matrix}\right.\end{matrix}\right.\)

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