Răspuns:
a = 6
b = 15
c =10
d =20
Explicație pas cu pas:
a/0,2=b/0,5=c/0,(3)=d/0,(6)=k ⇒a/2/10=b/5/10=c/3/9=d/6/9=k ⇒
10a/2=10b/5=9c/3=9d/6=k Simplificam si obtinem: 5a=2b=3c=3d/2=k ⇒
a=k/5 b= k/2 c=k/3 d=2k/3 Inlocuim aceste valori in relatia
3a-c+d-b=13 si obtinem 3·k/5-k/3+2k/3-k/2=13 ⇒Dupa aducerea la acelasi numitor obtinem: (18k+10k-15k)/30=13 ⇒13k/30=13 Impartim toata relatia prin 13 si obtinem k/30 = 1 deci k=30. Acum putem afla cele 4 numere: a=k/5 b= k/2 c=k/3 d=2k/3
a= 30/5= 6
b= 30/2= 15
c= 30/3=10
d=60/3=20