Решение задания 2:
A) $$-(1 - x) - (5,1 + x) = -1 + x - 5,1 - x = -6,1$$
B) $$-(a - x - 3) - (x - a + 2) = -a + x + 3 - x + a - 2 = 1$$
C) $$(a + 3,3 - a) - (3,3 + x) = a + 3,3 - a - 3,3 - x = -x$$
D) $$-(2,43 + x - b) - (2,43 + b - x) = -2,43 - x + b - 2,43 - b + x = -4,86$$
E) $$-(1,53 - x + 1) - (x - a - 2,53) = -1,53 + x - 1 - x + a + 2,53 = a + 1 - 1,53 + 2,53 = a + 1$$
Ответ:
A) $$-6,1$$
B) $$1$$
C) $$-x$$
D) $$-4,86$$
E) $$a + 1$$