Question

determinati numerele rationale a,b,c stiind ca sunt direct proportionale, respectiv cu 2,3,5 si ab+bc+ca=775

Answer 1

a supra 2=b supra 3=c supra 5=k =>a=2k
b=3k
c=5k
2k x 3k + 3k x 5k + 5k x 2k=775
6k+15k+10k=775
31k=775
k=775:31
k=25
a=25 x 2=50
b=25 x 3=75
c=25 x 5=125