Ответ:

  1. 7/15 + 3/4 = 28/60 + 45/60 = 73/60 = 1 13/60.
  2. 9 2/15 − 4 4/25 = 9 10/75 − 4 12/75 = 8 85/75 − 4 12/75 = 4 73/75.
  3. 2026 − 2022 2025/2026 = 2025 2026/2026 − 2022 2025/2026 = 3 1/2026.

Ответ: 1) 1 13/60; 2) 4 73/75; 3) 3 1/2026.