\(x^2-y^2-2y-1\\=x^2-(y^2+2y+1)\\=x^2-(y+1)^2\\=(x-y-1)(x+y+1)\)

I always prefer driving to (drive).....driven.....

driving

b) \(\left(x+3\right)^2-5x-15=0\\ \Leftrightarrow\left(x+3\right)^2-5\left(x+3\right)=0\\ \Leftrightarrow\left(x+3\right)\left(x+3-5\right)=0\\ \Rightarrow\left[{}\begin{matrix}x+3=0\\x-2=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=-3\\x=2\end{matrix}\right.\)

Vậy tập nghiệm của phương trình là : \(S=\left\{-3;2\right\}\)

c) \(2x^5-4x^3+2x=0\\ \Leftrightarrow2x\left(x^4-2x^2+1\right)=0\\ \Leftrightarrow2x\left(x^2-1\right)^2=0\\ \Rightarrow\left[{}\begin{matrix}2x=0\\\left(x^2-1\right)^2=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x^2=1\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=1\\x=-1\end{matrix}\right.\)

Vậy tập nghiệm của pt là : \(S=\left\{0;1;-1\right\}\)

1 Many households in my village raise cow

2 There is not much traffic in the countryside

3 What do you think about life in the mountains?

4 Playing traditional games is very interesting

5 Can you tell me a bit about Vietnamese's table manners?