Question

x(x-1)+x(x+3)=0

Answer 1

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

\(\Leftrightarrow x^2-x+x^2+3x=0\)

\(\Leftrightarrow2x^2+2x=0\)

\(\Leftrightarrow2x\left(x+1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}2x=0\\x+1=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-1\end{matrix}\right.\)

Vậy \(S=\left\{-1;0\right\}\)

Answer 2

Đề yêu cầu gì đó em?

Answer 3

x(x - 1) + x(x + 3) = 0

⇔ x² - x + x² + 3x = 0

⇔ 2x² + 2x = 0

⇔ 2x(x + 1) = 0

⇔ 2x = 0 hoặc x + 1 = 0

*) 2x = 0

⇔ x = 0

*) x + 1 = 0

⇔ x = -1

Vậy S = {-1; 0}

Answer 4

`x(x-1)+x(x+3)=0`

`<=>x(x-1+x+3)=0`

`<=>x(2x+2)=0`

\(< =>\left[{}\begin{matrix}x=0\\2x+2=0\end{matrix}\right.\\ < =>\left[{}\begin{matrix}x=0\\x=-1\end{matrix}\right.\)

Answer 5

\(x\left(x-1\right)+x\left(x+3\right)=0\\ \Leftrightarrow x\left(x-1+x+3\right)=0\\ \Leftrightarrow x\left(2x+2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\2x+2=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\2x=-2\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=-1\end{matrix}\right.\)

Vậy phương trình có tập nghiệm là: \(S=\left\{0;-1\right\}\)