x=suma
30%x+5000= prima data
x-30%x-5000=70%x-5000 =rest
(70%x-5000)*3/5+2000=(7x/10-5000 )*3/5+2000=42%x-3000= a2a data
70%x-5000-42%x+3000=28%x-2000 =rest
(28%x-2000)*50%+200=14%x-1000+200=14%x-800 = a 3-a data
30%x+5000+42%x-3000+14%x-800+24000=x
86%x+25200=x
14%x=25200
x=180000 lei
verificare
30%x+5000=180000*30%+5000=54000+5000=59000 lei
180000-59000=121000 lei
121000*3/5=72600 lei
121000-72600=48400 lei
48400*50%+200=24200+200=24400 lei
48400-24400=24000 lei