solve x^2 x=0.factorise.
\(x^2\pm x=0\\\\x(x\pm1)=0\iff x=0\ or\ x\pm1=0\\\\\boxed{x=0\ or\ x=\mp1}\\\\if\ x^2+x=0\ then\ x=0\ or\ x=-1\\if\ x^2-x=0\ then\ x=0\ or\ x=1\)
