Răspuns :
a+b+c=75
(a,b,c) d.p. (3,5,7)=>
a/3=b/5=c/7=k
a=3k
b=5k
c=7k
=> 3k+5k+7k=75
15k=75
K=75:15
K=5=>
a=5x3=15
b=5x5=25
c=5x7=35
(a,b,c) d.p. (3,5,7)=>
a/3=b/5=c/7=k
a=3k
b=5k
c=7k
=> 3k+5k+7k=75
15k=75
K=75:15
K=5=>
a=5x3=15
b=5x5=25
c=5x7=35