Răspuns :
Avem x+0,4=0,(5). Scriem acum ca fractie si avem: x+4/10=5/9 => x=5/9-2/5 => x=(25-18)/45=7 supra 45
x+0,4=0,(5)
x+4/10=5/9
x+2/5=5/9
45x+18=25
45x=25-18
45x=7
x=7/45
x=0,1(5)
x+4/10=5/9
x+2/5=5/9
45x+18=25
45x=25-18
45x=7
x=7/45
x=0,1(5)