x.(x-5)+x-5=o
=> x.(x-5)+(x-5)=0
=>(x-5)(x+1)=0
=> x-5=0 =>x=5
x+1=0 x=-1
x ( x - 5 ) + x - 5 = 0
x ( x - 5 ) + ( x - 5 ) = 0
(x - 5 ) ( x + 1 ) = 0
\(\Rightarrow\orbr{\begin{cases}x-5=0\\x+1=0\end{cases}\Rightarrow\orbr{\begin{cases}x=5\\x=-1\end{cases}}}\)
Vậy...
\(x.\left(x-5\right)+x-5=0\)
\(\Leftrightarrow x.\left(x-5\right)+\left(x-5\right)=0\)
\(\Leftrightarrow\left(x-5\right).\left(x+1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-5=0\\x+1=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=5\\x=-1\end{cases}}\)
