Question

Stiind ca $\frac{2x}{9y}$=0,2(7),calculati valoarea raportului $\frac{8x+5y}{9x-5y}$

Answer 1

Din egalitatea data obtinem
$\dfrac xy=\dfrac{25}{90}\cdot\dfrac92\Rightarrow \dfrac xy=\dfrac54\Rightarrow x=\dfrac{5y}{4}$ si inlocuim in fractia ce trebuie calculata
$...=\dfrac{8\cdot\dfrac{5y}{4}+5y}{9\cdot\dfrac{5y}{4}-5y}=\dfrac{40y+20y}{45y-20y}=\dfrac{60}{25}=\dfrac{12}{5}$