Question

Daca x/2 =y/9 atunci 10x - 2y /5x+y=........

Answer 1

x=2y/9
(20y/9-2y)/(10y/9+y)
Aduci la acelasi numitor si faci simplificari
(20y-18y)/(10y+9y)=2y/19y=2/19

Answer 2

$\bold{\frac{x}{2}=\frac{y}{9}}; \ \Rightarrow x=\frac{2y}{9} \\\\ \frac{10x-2y}{5x+y}=\frac{10 \cdot \frac{2y}{9}-2y}{5 \cdot \frac{2y}{9}+y}=\frac{\frac{20y}{9}-2y}{\frac{10y}{9}+y}=\frac{\frac{20y}{9}-\frac{18y}{9}}{\frac{10y}{9}+\frac{9y}{9}}=\frac{2y}{9}:\frac{19y}{9}=\frac{2y}{19y}=\boxed{\bold{\frac{2}{19}}}$