[tex]b) ( \frac{2}{3} )^x \cdot \frac{4}{9} = ( \frac{2}{3} )^7 \\
( \frac{2}{3} )^x \cdot ( \frac{2}{3} )^2 = ( \frac{2}{3} )^7 \\
x+2 = 7 \\
x =5 \\ \\
d) ( \frac{9}{25} )^x : ( \frac{3}{5} )^y = ( \frac{3}{5} )^3 \\ \\
( \frac{3}{5} )^{2x} : ( \frac{3}{5} )^y = ( \frac{3}{5} )^3 \\ \\
2x - y =3 \\
\text { x si y pot lua orice valori ce respecta conditia de mai sus, de exemplu: } \\
\text{x = 2 si y = 1 sau x = 3 si y = 3 ...}
[/tex]
