16-6×4:[13×2-1×8-(20×1-5×a)]+3×6=31
16-24:[26-8-(20-5a)] +18=31
16-24:[26-8-(20-5a)]=13
24:[26-8-(20-5a)]=-3
(26-8-20-5a)=-72
-8-20-5a= -98
-20-5a=-90
-5a=-70
a=-70:(-5)
a=14(FĂRA MINUS!!!!)
Sper să fie de folos! Spor!
