Question

Determinati nr a si b stiind ca sunt respectiv direct proportionale cu 3 si 5 si ca 5a+3b=60

Answer 1

a/3=b/5=k
a/3=k=>a=3k
b/5=k=>b=5k
5a+3b=60
5x3k+3x5k=60
15k+15k=60
30k=60
k=60/30
k=20
a=3k
a=3x20
a=60
b=5k
b=5x20
b=100
Sper ca te-am ajutat.