Răspuns :
Stim ca x/5 · 320 = 1600
Deci x/5 · 320/1 = 1600/1
x/5 = 1600/1 : 320/1
x/5 = 1600/1 · 1/320
x/5 = 5
x : 5 = 5
x = 5·5
x= 25
Deci x/5 · 320/1 = 1600/1
x/5 = 1600/1 : 320/1
x/5 = 1600/1 · 1/320
x/5 = 5
x : 5 = 5
x = 5·5
x= 25