1/2+3/5-2/3=1/3+3/5=4/8-2/3=2/5
64/70 - х + 26/70 = 5/70
64/70 - х = 5/70 - 26/70
64/70 - х = - 21/70
х = 64/70 - (- 21/70)
х = 85/70
-----------------------------------
64/70 - 85/70 + 26/70 = 5/70
- 21/70 + 26/70 = 5/70
5/70 = 5/70
1) 4=4 и 4=4
2) 5=5 и 5=5
3) 8=8 и 8=8
Подробно расписано на листке