42-...+8=43, ...+1-8=51, ...+6-40=23, 75+4- ...=63, 71 -...+5=76

42 - х + 8 = 43 -х = -42 - 8 + 43 -х = -7  х = 7 Проверка: 42 - 7 + 8 = 43;  35 + 8 = 43;  43 = 43 --------------------------------------- х + 1 - 8 = 51 х = -1 + 8 + 51 х = 58 Проверка: 58 + 1 - 8 = 51;    51 = 51 -------------------------------------- х + 6 - 40 = 23 х = 23 - 6 + 40 х = 57 Проверка: 57 + 6 - 40 = 23;  63 - 40 = 23;      23=23 -------------------------------------- 75 + 4 - х = 63 79 - х = 63 х = 79 - 63 х = 16 Проверка:75 + 4 - 16 = 63;    79 - 16 = 63;    63 = 63 ---------------------------------------- 71 - х + 5 = 76 -х = 76 - 71 - 5  х = 0 Проверка:  71 - 0 + 5 = 76;    76 = 76