Question

A,B,C sunt invers proportionale cu numerele 2,3,4,iar a+b+c=70.Aflati pe A,B,C.

Answer 1

Răspuns:

a•2=b•3=c•4=K

a•2=K => a=K/2

b•3=K => b=K/3

c•4=K => c=K/4

a+b+c=70

K/2+K/3+K/4=70/1

Aducem la acelsi numitor:

(K/2)•6=6K/12

(K/3)•4=4K/12

(K/4)•3=3K/12

6K/12+4K/12+3K/12=70/1

13K/12=70/1

K=(70•12)/13

K=840/13

a=32,30

b=21,53

c=16,15