Найдите значение выражения.

4. ((3 1/7 - 2 3/14) + (2 3/42 - 1 1/7)) = ((22/7 - 31/14) + (89/42 - 8/7)) = ((44/14 - 31/14) + (89/42 - 48/42)) = (13/14 + 41/42) = 39/42 + 41/42 = 80/42 = 40/21 = 1 19/21.