[5pliT]

25 - 45 = 16 - 36
25 - 45 + 81/4 = 16 - 36 + 81/4
5^2 - 2*5*9/2 + (9/2)^2 = 4^2 - 2*4*9/2 + (9/2)^2
(5-9/2)^2 = (4-9/2)^2
5 - 9/2 = 4 - 9/2
5 = 4
2 * 2 = 5