Răspuns :
( x - 3 ) +16 = 39
x - 3 = 39 - 16
x - 3 = 23
x = 23+ 3
x = 26
.......................
( 26 - 3 ) + 16 = 23 + 16 = 39
x - 3 = 39 - 16
x - 3 = 23
x = 23+ 3
x = 26
.......................
( 26 - 3 ) + 16 = 23 + 16 = 39