Question

Aflati ca 2x+6y/25x-y=58/41 daca si numai daca x si y sunt direct proportionale cu numerele 2 si 9.

Answer 1

{x,y}dp(2,9}
x/2=y/9=k
x/2=k⇒x=2k
y/9=k⇒y=9k
inlocuim in relatia (2x+6y)/(25x-y)=58/41
(2·2k+6·9k)/(25·2k-9k)=58/41
(4k+54k)/(50k-9k)=58/41
58k/41k=58/41                                 :58/41
k=1
x=2k=2
y=9

Answer 2

rezolvarea mai jos................