1.
a+b=74650
a/b=2/3 =>a=2b/3
2b/3 + b = 74650
2b+3b=74650 x 3
5b=74650 x 3
=>b=44790 =>a=29860
2.
(3 x 10425)/5 = 6255 km a parcurs avionul
=>10425-6255=4170 km mai are de parcurs avionul
3.
a-b=64218
b/a=2/6 =>b=2a/6 sau b=a/3
a - a/3 = 64218
3a-a=64218 x 3
2a=192654 =>a=96327
96327-b=64218 =>b=32109