Пошаговое объяснение:
12 5/13+у-9 9/13=7 7/13
12 5/13+у=7 7/13+9 9/13
12 5/13+у=16 16/13
у=16 16/13-12 5/13
у=4 11/13
2 5/13 + у - 9 9/13 = 7 7/13
31/13 + y - 126/13 = 98/13
-95/13 + y = 98/13
y = 98/13 + 95/13
y = 193/13
y = 14 11/13
