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?

1 A balance diet is very important for a good health

2 Running in the morning or playing a sport helps us to have a healthy body

3 Native residents are trying to reserve their culture and tradition

4 If you practice Engish everyday, you can speak it fluently

a) 2x(x² - xy³)

= 2x.x² - 2x.xy³

= 2x³ - 2x²y³

b) (12x³y⁵ - 21x⁴y²) : 3x²y²

= 12x³y⁵ : 3x²y² - 21x⁴y² : 3x²y²

= 4xy³ - 7x²

a, 2\(x\).(\(x^2\) - \(xy^3\))

= 2\(x^3\) - 2\(x^2\)y³

b, (12\(x^3\)y⁵ - 21\(x^4\)y²) :(3\(x^2\)y²)

=    3\(x^2\).y².(4\(xy^3\) - 7\(x^2\))

= 4\(xy^3\) - 7\(x^2\)