Which of the following is a linear equation?
 
(i) \((y-5) = 2y +(y-1)\)  \(=\)
 
(ii) \(y(y-3) = y^2 + 3y + 5\) \(=\)  
 
(iii) \(2x(x-1) = 2x^2 + 5\) \(=\)