Question

Determinati numerele a si b stiind ca sunt respectiv direct proportionate cu 3 si 5 si ca 5a+3b=60 VA ROG AM NEVOIE !!

Answer 1

a/3=b/5    ;=>  5a=3b   ;  =>a=3b /5
5a +3b =60
5*3b /5   +3b  =60   ;   numitor 5
15b +15b =300
30b =300
b =10
a =3b/5
a =3*10/5 =30/5 =6
verif  ;   5*6 +3*10 =30+30 =60

Answer 2

a =3k
b=5k
3·5k+5 ·3k= 60
15k+15k=60
30k=60
k=2
a=3x k=3x2=6 
b= 5xk=5x2=10