Номер 808

Розв’яжіть рівняння:

1) 52/63 – х/63 = 25/63

   х/63 = 52/63 – 25/63

   х/63 = (52–25)/63

   х/63 = 27/63

   х = 27 

2) х/38 + 14/38 = 23/38

х/38 = 23/38 – 14/38

х/38 = (23–14)/38

х/38 = 9/38

х = 9

3) (12/13 + х) – 5/13 = 9/13

12/13 + х = 9/13 + 5/13

12/13 + х = (9+5)/13

12/13 + х = 14/13

х = 14/13 – 12/13

х = (14–12)/13

х = 2/13

4) (х – 21/31) + 14/31 = 25/31

х – 21/31 = 25/31 – 14/31

х – 21/31 = (25–14)/31

х – 21/31 = 11/31

х = 11/31 + 21/31

х = (11+21)/31

х = 32/31