Răspuns :
101 - ( 81 : x - 9 ) = 101
81 : x - 9 = 101 - 101
81 : x - 9 = 0
81 : x = 9 + 0
81 : x = 9
x = 81 : 9
x = 9
81 : x - 9 = 101 - 101
81 : x - 9 = 0
81 : x = 9 + 0
81 : x = 9
x = 81 : 9
x = 9
909:9 - ( 9* 9:x - 9 ) = 101
101 - (81:x - 9 ) = 101
81:x - 9 = 101 - 101
81:x - 9 = 0
81:x = 9
x = 81:9
x = 9
101 - (81:x - 9 ) = 101
81:x - 9 = 101 - 101
81:x - 9 = 0
81:x = 9
x = 81:9
x = 9