ОлегСилионов Вариант В1
а:  ... = -2.8 -1.65 -0.75 = -5.2 (5_1/5)
б: ... = -8 + 4_9/21 + 2_11/21 = -1_1/21
в: ... = 2_3/15 - 4_5/15 - 1_13/15 = -4
B2
а: ... = -1.9 -2.15 -1.25 = -5.3
б: ... = -6 +2_35/45 +1_6/45 = -2_4/45
в: ... = 3_8/28 - 1_7/28 -1_1/28 = 1