a) \(x^2-2=x-2\)
\(\Leftrightarrow x^2-x=-2+2\)
\(\Leftrightarrow x^2-x=0\)
\(\Leftrightarrow x\left(x-1\right)=0\)
\(\Leftrightarrow\hept{\begin{cases}x=0\\x-1=0\end{cases}\Leftrightarrow}\hept{\begin{cases}x=0\\x=1\end{cases}}\)
\(S=\left\{0;1\right\}\)
b) \(\left(x+1\right)^3=x+1\)
\(\Leftrightarrow\left(x+1\right)^3-\left(x+1\right)=0\)
\(\Leftrightarrow\left(x+1\right)\left(x^2-x+1-1\right)=0\)
\(\Leftrightarrow\left(x+1\right)\left(x^2-x\right)=0\)
\(\Leftrightarrow x\left(x+1\right)\left(x-1\right)=0\)
\(\Leftrightarrow\hept{\begin{cases}x=0\\x+1=0\\x-1=0\end{cases}\Leftrightarrow}\hept{\begin{cases}x=0\\x=-1\\x=1\end{cases}}\)
\(S=\left\{-1;0;1\right\}\)
(Nhớ k cho mình với nhé!)
a; x2 - 2 = x - 2
x2 - 2 - (x - 2) = 0
x2 - 2 - x + 2 = 0
x2 - x = 0
x.( x -1 ) = 0
=> x=0 hoặc x - 1 = 0
x=0 hoặc x = 1
