Question

tìm x, biết:

2(x+5)+x²+5x=0

Answer 1

=>(x+5)(x+2)=0

=>x=-5 hoặc x=-2

Answer 2

Đề sai nên mình sửa lại giữa x² với 5x thành dấu nhân nhé bạn :))

\(2\left(x+5\right)+x\left(x+5\right)=0\)

\(\left(2+x\right)\left(x+5\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}2+x=0\\x+5=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=-5\end{matrix}\right.\)

Answer 3

\(2\left(x+5\right)+x\left(x+5\right)=0\\ \left\{{}\begin{matrix}x+5=0\\2+x=0\end{matrix}\right.\left\{{}\begin{matrix}x=0-5=-5\\x=0-2=-2\end{matrix}\right.\)

Answer 4

\(2\left(x+5\right)+x^2+5x=0\)

\(2\left(x+5\right)+x\left(x+5\right)=0\)

\(\left(x+5\right)\left(2+x\right)=0\)

\(\Rightarrow x+5=0;2+x=0\)

*) \(x+5=0\)

\(x=-5\)

*) \(2+x=0\)

\(x=-2\)

Vậy \(x=-5\); \(x=-2\)