Ta có \(\frac{x-1}{3}=\frac{y-3}{1}=\frac{z-3}{5}\)

=> \(\frac{3x-3}{9}=\frac{2y-6}{2}=\frac{z-3}{5}\)

Áp dụng tính chất dãy tỉ số bằng nhau ta có \(\frac{x-1}{3}=\frac{y-3}{1}=\frac{z-3}{5}=\frac{3x-3}{9}=\frac{2y-6}{2}=\frac{z-3}{5}=\)                                                                                                                                                                     \(=\frac{3x-3+2y-6-z+3}{9+2-5}=\frac{\left(3y+2y-z\right)-6}{6}=\frac{-6}{6}=-1\)

=> \(\hept{\begin{cases}x-1=-3\\y-3=-1\\z-3=-5\end{cases}}\Rightarrow\hept{\begin{cases}x=-2\\y=2\\z=-2\end{cases}}\)

Ta có :

\(\frac{x-1}{3}=\frac{y-3}{1}=\frac{z-3}{5}\)

\(\Rightarrow\frac{3x-3}{9}=\frac{2y-6}{2}=\frac{z-3}{5}\)

Áp dụng tính chất dãy tỉ số bằng nhau :

\(\frac{x-1}{3}=\frac{y-3}{1}=\frac{z-3}{5}=\frac{3x-3}{9}=\frac{2y-6}{2}=\frac{z-3}{5}\)

\(=\frac{3x-3+2y-6-z+3}{9+2-5}=\frac{\left(3y+2y-z\right)-6}{6}=\frac{-6}{6}=-1\)

\(\Rightarrow\hept{\begin{cases}x-1=-3\\y-3=-1\\z-3=-5\end{cases}\Rightarrow\hept{\begin{cases}x=-2\\y=2\\z=-2\end{cases}}}\)

Chiều cao thửa ruộng là:

        21×2:3=14(m)

Tổng của đáy lớn và đáy bé là:

        210×2:14=30(m)

Đáy lớn thửa ruộng là:

       (30+6):2=18(m)

Đáy bé thửa ruộng là:

        18-6=12(m)

Chiều cao..là:

21.2:3=14( m2) 

Tổng độ dài...là:

210:14.2=30(m)

Đáy lớn...là:

(30+6):2=18(m)

Đáy bé... là:

30-18=12(m)

Đ/s: Đáy lớn:18m

        Đáy bé:12m

\(x=\sqrt{5+\sqrt{13+\sqrt{5+\sqrt{13...}}}}\)

\(\Rightarrow x^2-5=\sqrt{13+\sqrt{5+\sqrt{13...}}}\)

\(\Rightarrow x^4-10x^2+25-13=x\)

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

\(\Leftrightarrow\left(x-3\right)\left[\left(x+3\right)\left(x+1\right)\left(x-1\right)-1\right]=0\)

Dễ thấy \(x=\sqrt{5+\sqrt{13+\sqrt{5+\sqrt{13...}}}}>\sqrt{4}=2\)nên \(\left(x+3\right)\left(x+1\right)\left(x-1\right)-1>5\cdot3\cdot1-1=14>0\)nên x = 3

x² - xy = 4

=> x ( x - y ) = 4

Vậy các cặp ( x ; y ) thỏa mãn đề bài là : ( 1 ; - 3 ) ; ( 4 ; 3 ) ; ( - 1 ; - 3 ) ; ( - 4 ; - 3 ) ; ( 2 ; 0 ) ; ( - 2 ; 0 )
 

Ta có :

2⁴⁵ = ( 2³ )¹⁵ = 8¹⁵

Vì 8¹⁵ < 12¹⁵

=> 12¹⁵ > 2⁴⁵

Ta có :

   \(12^{15}\)

\(2^{45}=\left(2^3\right)^{15}=8^{15}\)

\(\Rightarrow\)\(12^{15}\)>   \(8^{15}\)

hay  \(12^{15}\)>   \(2^{45}\)

Giúp với mn ơi!!

\(3^{2019}+4^{2019}\)\(=\left(3^3\right)^{673}+\left(4^3\right)^{673}\)\(⋮3^3+4^3=91⋮13\)

Vậy: \(3^{2019}+4^{2019}⋮13\)

1.You should eat more vegetables(vegetables), and you will feel healthier.

2. The exam ination is coming  watch less TV (TV)

3. You look lack of sleep sleep more.(sleep)

4.Eat more fish ( fish), and you will smarter.

5.You are putting on weight  eat less fast food..(fast food)

6.try to talk less (try/ talk) when you have a sore throat

7. You have a cough you should drink more warm water(warm water).

8.Sunbathe less (Sunbathe) or you ll' get sunburnt

Make imperatives with more or less

1.You should eat more vegetable, and you will feel heathier

2.The examination is coming.watch less TV

3.You look lack of sleep.(sleep) more

4. Eat more(fish), and you wiil be smarter 

5.You are putting on weight (fast food) so eat less fast food.

6.(try/talk)Try to talk  when you have a throat

7. You have a cough (warm water) , you shouls drink more warm water .

8.less (sunburn),or you'll get sunburnt 

ơ

Rõ ràng có câu hỏi mà

bn đăng lại ik

hello

Vietnamese students have fewer vacations than American ones

=>American students have longer vacations than Vietnamese ones.

Vietnamese students have fewer vacations than American ones

=>American students have more vacations than Vietnamese ones.