Question

Tình x biết a) x²(x-2)-x-2=0

b) 5(x-11)-x+11=0

Answer 1

\(a,x^2\left(x-2\right)-\left(x-2\right)=0\)

\(\Rightarrow x^2\left(x-2\right)-\left(x-2\right)=0\)

\(\Rightarrow\left(x-2\right)\left(x^2-1\right)=0\)

\(\Rightarrow\left(x-2\right)\left(x-1\right)\left(x+1\right)=0\)

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

\(b,5\left(x-11\right)-x+11=0\)

\(\Rightarrow5\left(x-11\right)-\left(x-11\right)=0\)

\(\Rightarrow\left(x-11\right)\left(5-1\right)=0\)

\(\Rightarrow4\left(x-11\right)=0\)

\(\Rightarrow x-11=0\Rightarrow x=11\)

Answer 2

a)fix đề : \(x^2\left(x-2\right)+x-2=0\)

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

b)

\(5\left(x-11\right)-x+11=0\\ \Leftrightarrow\left(x-11\right)\left(5-1\right)=0\\ \Leftrightarrow x-11=0\Leftrightarrow x=11\)