undeva nua ai inchis paranteza patrata, dar rezolvi parantezele intai pana la x
[31440+1040:(150-2400:120)x20]:x+1000=1080
[31440+1040:(150-20)x20]:x+1000=1080
(31440+1040:130x20):x+1000=1080
(31440+ 8x20):x+1000=1080
(31440+160): x+1000=1080
31600 :x+1000=1080
31600:x=1080-1000
31600:x=80
x=31600:80
x=395