Aflati nr necunoscut:
[(x:7-1):4×12-3×5]:9+11=16


Răspuns :

......................
Vezi imaginea EAGLEEYES
[(x:7-1):4×12-3×5]:9=16-11
[(x:7-1):4×12-3×5]=5×9
[(x:7-1):4×12-3×5]=45
(x:7-1):4×12-3=45:5
(x:7-1):4×12=9+3
(x:7-1):4=12:12
(x:7-1)=1×4
(x:7-1)=4
x:7=4+1
x:7=5
x=7×5
x=35