Question

Numerele a, b si c sunt direct proportionate cu 3, 7 si 9. Determinati numerele stiind ca suma lor este egala cu 38. Va rog!!!!!!!

Answer 1

a,b,c=?
a+b+c=38

{a,b,c} d.p. {3,7,9} <=> $\frac{a}{3}= \frac{b}{7} = \frac{c}{9} =\ \textgreater \ \frac{a+b+c}{3+7+9} = \frac{38}{19} =2$=k
k=2
a/3=2 =>a=6
b/7=2 =>b=14
c/9=2 =>c=18