Question

Daca a/3=b/4=c/7 si a+b+c=70,afla numerele a,b,c

Answer 1

Acele rapoarte sunt egale, sa zicem cu un numar K.
$\frac{a}{3} =\frac{b}{4} = \frac{c}{7}=k$
Asta inseamna ca 
a=3k
b=4k
c=7k

Relatia a+b+c=70 devine
3k+4k+7k=70
14k=70
k=5

Revenim la a,b si c:
a=3*5=15
b=4*5=20
c=7*5=35

Answer 2

a/3=b/4=c/7=m
a=3m  b=4m  c=7m
a+b+c=70
3m+4m+7m=70
14m=70
m=70:14
m=5
a=15
b=20
c=35
proba
15+20+35=70