9/52
Пошаговое объяснение:
7/13 - (12/26 + (-5/52))
12/26 + (-5/52)= 12/26 - 5/52 = 24/52 - 5/52 = 19/52
7/13 - 19/52 = 28/52 - 19/52 = 9/52
9/52
Пошаговое объяснение:
7/13 - (12/26 + (-5/52))
1 действие12/26 + (-5/52)= 12/26 - 5/52 = 24/52 - 5/52 = 19/52
2 действие7/13 - 19/52 = 28/52 - 19/52 = 9/52