А) (-3 5/8 + 7,6) - (10,8 - 8 3/4) = (-3 5/8 + 7 6/10) - (10 8/10 - 8 3/4) = (-29/8 + 76/10) - (108/10 - 35/4) = (-145+304)/40 - (216-175)/20 = 159/40 - 29/20 = (159-58)/40 = 101/40 = 2 21/40
б) -(5 4/9 - 6 5/12) + (-3 2/3 - 5/9) = -(49/9 - 77/12) + (-11/3 - 5/9) = -(148-231)/36 + (-33-5)/9 = -(-83/36) + (-38/9) = 83/36 - 38/9 = (83-152)/36 = 69/36 = 1 33/36 = 1 11/12