Răspuns:
x:20:4*(1000*100):500=600
x:20:4*(1000*100)=600*500
x:20:4*(1000*100)=300000
x:20:4*1000=300000:100
x:20:4*1000=3000
x:20:4=3000:1000
x:20:4=3
x:20=3*4
x:20=12
x=12*20
x=240
Verificare:
240:20:4*(1000*100):500=
12:4*100000:500=
3*100000:500=
300000:500=
600