Question

Va rog dau coroana!.​

Answer 1

Daca x/y=3/5 => notam cu k relatia
=> x=3k și y=5k
=> 2•3k+3•5k/5•3k-2•5k
=>6k+15k/15k-10k
=> 21k/5k
=> 2x+3y/5x-2y =21k/5k (împărțim relația la k)
=> 2x+3y/5x-2y= 21/5

Answer 2

$\it \dfrac{x}{y}=\dfrac{3}{5} \Rightarrow \dfrac{x}{y}=0,6 \Rightarrow x=0,6y\ \ \ \ \ (*)\\ \\ \\ \dfrac{2x+3y}{5x-2y}\ \stackrel{(*)}{=}\ \dfrac{2\cdot0,6y+3y}{5\cdot0,6y-2y}=\dfrac{4,2y}{y}=4,2=\dfrac{\ \ 42^{(2}}{10}=\dfrac{21}{5}$