Question

o preblema  direct proportionala  cu rezolvare 

Answer 1

Aflati numerele a ,b si c  daca sunt direct proportionate cu 2 , 5 si respectiv 7 si a+b+c=28.
a.................2
b.................5
c.................7
a+b+c=28
a/2 =b/5=c/7
a=2k
b=5k
c=7k
2k+5k+7k=28
14k=28/:14
k=2
a=2k-->a=4
b=5k-->b=10
c=7k--->c=14