i am not able to understand the fo?lling solution of the question " an item was sold for 1200 at a loss of 25% find the cost price" ?

Let the CP = Rs.x

SP = Rs. 1200

Loss % = 25%

25 x = 100  (x - 1200)

x = 4 (x - 1200) ⇒ x = 4x - 4800

 ⇒ - 3x = - 4800 ⇒ x = 1600

so, CP = Rs. 1600