Question

Trei bucati de sfoara masoara impreuna 7500 m. Primele doua bucati au impreuna 5750 m, iar ultimele doua 4958 m. Cati metri masoara fiecare bucata de sfoara?

Answer 1

a+b+c=7500
a+b=5750
b+c=4958

(a+b)+c=7500⇒5750+c=7500⇒c=7500-5750⇒c=1750
a+(b+c)=7500⇒ a+4958=7500⇒a=7500-4958⇒a=2542 
a+b=5750⇒2542+b=5750⇒b=5750-2542⇒b=3208

verificare a+b+c=2542+3208+1750=5750+1750=7500