Răspuns :
( 3 x - 5 + 5 ) : 9 + 89 = 100
( 3 x - 5 + 5 ) : 9 = 100 - 89
3 x - 5 + 5 = 11 × 9
3 x = 99 - 5 + 5
3 x = 94 + 5
3 x = 99
x = 99 : 3
( 3 x - 5 + 5 ) : 9 + 89 = 100
( 3 x - 5 + 5 ) : 9 = 100 - 89
3 x - 5 + 5 = 11 × 9
3 x = 99 - 5 + 5
3 x = 94 + 5
3 x = 99
x = 99 : 3