Which of the following is a linear equation?
 
(i) \((x-1) = (2x+3)\)  \(=\)
 
(ii) \((y-5)(y+5) = 0\) \(=\)  
 
(iii) \(2(x+1) + 5 = 5(x-2) + 3\) \(=\)