Question

Determinati numerele rationale pozitive x si y care indeplinesc conditiile x supra y= 5 supra 3 si 3x + 4y =81

Answer 1

x/y=5/3
3x=5y
x=5y/3
inlocuim in relatia 3x+4y=81
3·5y/3+4y=81
15y/3+4y=81
(15y+4y·3)/3=81
(15y+12y)=81·3
27y=243
y=243/27
y=9

x=5y/3=(5·9)/3=15
x=15