Question

15:[11-(7*5-9*9:x:3):8+2*4]*3=3 si 
[1997+39+1202-2005]*1997

Answer 1

15:[11-(35-81:x:3):8+8]=3:3
15:[11-(35-81:x:3):8+8=1
[11-(35-81:x:3):8+8]=15:1
[11-(35-81:x:3):8+8]=15
11-(35-81:x:3):8=15-8
11-(35-81:x:3):8=7
(35-81:x:3):8=11-7
(35-81:x:3):8=4
35-81:x:3= 8x4
35-81:x:3=32
81:x:3=35-32
81:x:3=3
81:x=3x3
81:x=9
x=81:9
x=9