Решите уравнение
(26+37+x)+(44-13-18)-16-18-26=51

( 26 + 37 + x ) + ( 44 - 13 - 18 ) - 16 - 18 - 26 =51

( 63 + х ) + ( 44 - 13 - 18 ) - 16 - 18 - 26 =51

( 63 + х ) + 13 - 16 - 18 - 26 = 51

63 + х  = 51 - 13 + 16 + 18 + 26

63 + х = 98

х = 98 - 63

х = 35

проверка:

( 26 + 37 + 35 ) + ( 44 - 13 - 18 ) - 16 - 18 - 26 = 98 + 13 - 16 - 18 - 26 =

= 111 - 16 - 18 - 26 = 51