(1,25-1/2):75/2009*5/2009

(1,25-1/2):75/2009*5/2009 = (5/4 - 1/2) * 2009/75 * 5/2009 = 3/4 * 1/75 * 5 = 1/4 * 1/25 * 5 = 1/4 * 1/5 = 1/20

(1,25-1/2):75/2009*5/2009= (1,25-0,5):75/2009*5/2009= 0,75*2009/75*5/2009= 3/4*1/75*5= 1/4*1/25*5= 1/4*1/5=1/20