Tema 3

V=20 lei
Umgx=10-x
Umgy=28-2y
Px=1 leu
Py=2 lei
Qx=?
Qy=?

Umgx/Umgy=Px/Py <=>10-x/28-2y=1/2 <=> 20-2x=28-2y <=> -2x-2y=28-20 <=> -2x-2y=8
V=(Px * Qx) + (Py * Qy) <=>20=x+2y <=> x+2y=20
-2x+2y=8            -2x+2y=8
                   <=>
x+2y=20|*2          2x+4y=40
                            _________
                             //   6y=48 => y=48/6=8
<=>y=8                   y=8              y=8               y=8
                       <=>             <=>             <=>
      2x+32=40         2x=8             x=8/2            x=4

Qx=4 , Qy=8