Answer :

[tex]x\cdot x=2x\\ x^2-2x=0\\ x(x-2)=0\\ x=0 \vee x=2 [/tex]
[tex]x*x=2x \\ x^2=2x \\ x^2-2x=0 \\ x(x-2)=0 \\ x = 0 \ \ \ \vee \ \ \ x-2=0 \ therefore \ x= 2[/tex]