đoạn trích nào nhỉ

đoạn trích nào vậy bạn

a: \(A=3+3^2+\cdots+3^{2019}\)

=>\(3A=3^2+3^3+\ldots+3^{2020}\)

=>3A-A=\(3^2+3^3+\cdots+3^{2020}-3-3^2-\cdots-3^{2019}\)

=>2A=\(3^{2020}-3\)

=>2A+3=\(3^{2020}\)

=>\(3^{x}=3^{2020}\)

=>x=2020

b: ƯCLN(a;b)=5

=>a⋮5 và b⋮5

ab=300

mà a⋮5 và b⋮5

nên (a;b)∈{(5;60);(60;5);(10;30);(30;10);(15;20);(20;15)}

mà ƯCLN(a;b)=5

nên (a;b)∈{(5;60);(60;5);(15;20);(20;15)}

25) How can strong earthquakes affect land features? Strong earthquakes can cause the ground to crack or shift, create landslides, trigger tsunamis, and permanently raise or lower sections of the Earth's crust (uplift and subsidence).

26) Explain what happens when locked slabs break free. When locked tectonic slabs suddenly break free, the stored elastic energy is released as seismic waves, causing the ground to shake (an earthquake).

27) What can cause weathering? Weathering is caused by physical forces (like ice wedging, plant roots, and temperature changes) and chemical processes (like water reacting with minerals, acid rain, or oxidation).

28) How does erosion shape and change the land? Erosion picks up and moves weathered rock and soil to new locations. This process wears down mountains, carves out valleys and canyons, and creates new landforms like deltas through deposition.

29) How does gravity cause erosion? Gravity acts as a direct force that pulls rocks, soil, and debris downward, leading to mass movements such as landslides, mudslides, rockfalls, and soil creep.

\(\left(2x+3\right)^3=\left(-25\right).\left(-5\right)\)

\(\Leftrightarrow\left(2x+3\right)^3=125\)

\(\Leftrightarrow\left(2x+3\right)^3=5^3\)

\(\Leftrightarrow2x+3=5\)

\(\Leftrightarrow2x=2\)

\(\Leftrightarrow x=1\)

\(\left(2x+3\right)^3=\left(-25\right).\left(-5\right)\)

\(\Leftrightarrow\left(2x+3\right)^3=5^3\)

\(\Leftrightarrow2x+3=5\)

\(\Leftrightarrow2x=2\)

\(\Leftrightarrow x=1\)

\(\Leftrightarrow x\left(y+1\right)+y+1=31\\ \Leftrightarrow\left(x+1\right)\left(y+1\right)=31=31\cdot1\)

\(TH_1:\left\{{}\begin{matrix}x+1=31\\y+1=1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=30\\y=0\end{matrix}\right.\rightarrow\left(30;0\right)\\ TH_2:\left\{{}\begin{matrix}x+1=1\\y+1=31\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0\\y=30\end{matrix}\right.\rightarrow\left(0;30\right)\)

Vậy \(\left(x;y\right)\in\left\{\left(30;0\right);\left(0;30\right)\right\}\)

\(\Leftrightarrow xy+x+y+1=31\Leftrightarrow\left(x+1\right)\left(y+1\right)=31\)

Do x, y nguyên dương nên xảy ra các TH sau:

TH1: \(\left\{{}\begin{matrix}x+1=1\\y+1=31\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}x=0\\y=30\end{matrix}\right.\)(LOẠI)

TH2:\(\left\{{}\begin{matrix}x+1=31\\y+1=1\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}x=30\\y=0\end{matrix}\right.\)(LOẠI)

Vậy không có x, y nguyên dương thoả mãn đề bài.

A thousand years ago, my area was a vibrant part of the Champa Kingdom. The people living here were the Cham, who were skilled sailors and traders. They had lived in this coastal region for centuries, settling along the fertile river banks and near the sea to facilitate trade with merchants from India and China.

Life was deeply connected to nature and religion. Most people were farmers who grew rice, or fishermen who relied on the abundant sea. They wore simple yet elegant clothing made of light cotton, often wrapped as sarongs to stay cool in the tropical heat. Their diet was rich in seafood, tropical fruits, and rice, which they cooked with aromatic spices.

The Cham people were also master builders. They left behind magnificent brick temples and sandstone sculptures dedicated to their gods. Even today, we can still find the ruins of these ancient towers standing on hills, serving as a reminder of a powerful and artistic civilization that flourished here long ago.

b: T=(-1)+(-1)+...+(-1)

=-1011

làm giúp mình câu a nữa nhé 'v'

a)x=-2

b) y=10

c)x=-5

d) x=-12

\(a,\dfrac{x}{3}=\dfrac{6}{-9}\\ \Rightarrow x=-\dfrac{2}{3}.3\\ \Rightarrow x=-2\\ b,\dfrac{4}{y}=\dfrac{-2}{-5}\\ \Rightarrow y=4:\dfrac{2}{5}\\ \Rightarrow y=10\\ c,\dfrac{-2}{3}=\dfrac{x-1}{6}\\ \Rightarrow3x-3=-12\\ \Rightarrow3x=-9\\ \Rightarrow x=-3\\ d,\dfrac{3}{x}=\dfrac{6}{-24}\\ \Rightarrow x=3:-\dfrac{1}{4}\\ \Rightarrow x=-12\)

\(a,\dfrac{3}{4}=\dfrac{15}{20}\\ \dfrac{7}{10}=\dfrac{14}{20}\\ b,\dfrac{-5}{14}=\dfrac{-55}{154}\\ \dfrac{9}{22}=\dfrac{63}{154}\\ \dfrac{-4}{7}=\dfrac{-36}{63}\\ \dfrac{8}{9}=\dfrac{56}{63}\\ \dfrac{-10}{21}=\dfrac{-30}{63}\)

bạn ơi còn thiếu câu c