№3 Раскройте скобки и упростите выражение

Решение:
1. (x - (x - y)) = (x - x + y) = (y)

2. (a - (b + a)) = (a - b - a) = (-b)

3. ((m - n) + n) = (m - n + n) = (m)

4. ((x + y) - y) = (x + y - y) = (x)

5. (5 - (3 + x)) = (5 - 3 - x) = (2 - x)

6. (-x + (x + 2.7)) = (-x + x + 2.7) = (2.7)

7. (-(-b + 3.8) + 0.7) = (b - 3.8 + 0.7) = (b - 3.1)

8. (4.74 - (2a + 3.7)) = (4.74 - 2a - 3.7) = (1.04 - 2a)