Ответ:
14 − 8 + 7 = 6 + 7 = 13.
16 − 9 + 6 = 7 + 6 = 13.
6 + 8 − 9 = 14 − 9 = 5.
16 − (4 + 7) = 16 − 11 = 5.
12 + (13 − 8) = 12 + 5 = 17.
13 − (4 + 9) = 13 − 13 = 0.
14 − 8 + 7 = 6 + 7 = 13.
16 − 9 + 6 = 7 + 6 = 13.
6 + 8 − 9 = 14 − 9 = 5.
16 − (4 + 7) = 16 − 11 = 5.
12 + (13 − 8) = 12 + 5 = 17.
13 − (4 + 9) = 13 − 13 = 0.