96 - 3( x+ 1 ) = 42

       3( x + 1 ) = 96 - 42

       3( x + 1 ) =    54

           x + 1   = 54 : 3

           x + 1   =    18

           x         = 18 - 1

           x         =    17

12x - 33 = 3 ^ 2 . 3 ^ 3

12x - 33 =   9  . 27

12x - 33 =      243

12x        = 243 + 33

12x        =      276

    x        = 276 : 12

    x        =     23

Ta có 2^x + 1 = y² 

<=> 2^x = (y - 1)(y + 1)

Đặt  y - 1 = 2ⁿ (  n > 0)

=> 2^x = 2ⁿ (2ⁿ + 2)

Với n = 1 thì y = 3; x = 3

Với n \(\ge2\) thì 2​​ⁿ⁺¹ > 2^n-1 \(\ge2\)

Ta có 2^x = 2ⁿ⁺¹ (2^n-1 + 1)

Ta thấy (2^n-1 + 1) là 1 số lẻ nên không tồn tại n \(\ge2\)thỏa bài toán

Vậy x = y = 3

Mình không biết đúng không. Bạn kiểm tra lại nha

\(\frac{x}{3}=\frac{y}{4}\) và x + y = 14

áp dụng t/c DTSBN ta có:

\(\frac{x}{3}=\frac{y}{4}=\frac{x+y}{3+4}=\frac{14}{7}=2\)

=> \(\hept{\begin{cases}\frac{x}{3}=2\\\frac{y}{4}=2\end{cases}}\)

=> \(\hept{\begin{cases}x=6\\y=8\end{cases}}\)

câu kia tương tự!!

chúc bạn học tốt!! ^^

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Fill in the blanks with the correct modal verb: can, can't, should, shouldn't, must, mustn't, have to, dont' have to.

1. Can you help me, please?
2. You should do more sport if you want to lose weight.
3. You have to do your homework first if you want me to let you go out with your friends.
4. He has just broken his leg so he mustn't play football.
5. Drivers mustn't drive over the speed limit.
6. I .can't speak Chinese: it's too difficult!
7. She should take an umbrella; it's going to rain!
8. We mustn't take photos inside; it's not forbidden.
9. I think we shouldn't take this road; it's not on my map!
10. You look pale! You should sit down and have a glass of water.
11. We must stop when the traffic light is red.
12. How should you say such a thing?
13. You can take the blue one: it suits you!
14. You musn't smoke so much: it's bad for health.
15. We should book a table in advance. There's plenty of room in that restaurant on Mondays. 16. You shouldn't forget her birthday again. 17. You should brush your teeth three times a day. 18. We don't have to drive fast, we have a plenty of time,

noooooooooooooooooooooooooooooooooooooooo

Bạn "Nguyễn Duy Anh" ơi , mình cảm ơn bạn đã trả lời , nhưng theo mình thì x phải = 0 . Nhưng mình ko biết cách trình bày bài làm .

xin lỗi mk bận nên

ko tìm được x nhỉ

Nữa chu vi hình chữ nhật là : 36 : 2 = 18 (cm)

Chiều rộng hình chữ nhật là : (18 - 2) : 2 =8 (cm)

Chiều dài hình chữ nhật là : 8 + 2 = 10 (cm)

Diện tích hình chữ nhật là :  10 x 8 = 80 (cm²)

        Đáp số : 80 cm²

1. She has played the piano for 5 years.

2. It hasn't snowed for 2 weeks.

3. I have never met him before.

Hoặc : I haven't ever met him before.

4. I have never read such a interesting novel before.

Ta đổi:

144=12^2

=>x^2=12^2