71/2:1,8+22/3*(0,75-1.2) = 15/2 : 18/10 + 8/3 * (-0,45) = 15/2 * 10/18 + 8/3 * (-45/100) = 25/6 - 30/25 = 25/6 - 6/5 = 19/5 = 3 i 4/5