Question

помогите срочно!!!!​

Answer 1

4 → + а → 4 + а

4 → + 2 → 6

4 → + 5 → 9

4 → + 3 → 7

9 → - а → 9 - а

9 → - 2 → 7

9 → - 5 → 4

9 → - 9 → 0