(3,9-5,80)-(-1/45-7/9)+1,1

(3,9 - 5,80) - (-1/45 - 7/9) + 1,1 = (3 9/10 - 5 80/100) - (-1/45 - 7/9) + 1 1/10 = (39/10 - 580/100) + (1/45 + 7/9) + 11/10 = (39/10 - 58/10) + (1/45 + 35/45) + 11/10 = (39 - 58)/10 + 11/10 + (1 + 35)/45= (39 - 58 + 11)/10 + (1 + 35)/45 = (50 - 58)/10 + 36/45 = -(-50 + 58)/10 + 4/5 = -(58 - 50)/10 + 8/10 = -8/10 + 8/10 = (-8 + 8)/10 = (8 - 8)/10 = 0/10 = 0

Ответ: 0