Răspuns:
[tex]\frac{x}{y} =\frac{7}{9}[/tex]⇒ 7y=9x
d) [tex]\frac{18x-14y+25}{12+9x-7y} =\frac{18x-18x+25}{12+9x-9x}=\frac{25}{12}[/tex]
e) [tex]\frac{4+27x-21y}{9x+5-7y}=\frac{4+21y-21y}{7y+5-7y}=\frac{4}{5}[/tex]
f)[tex]\frac{2,5+4,5x-3,5y}{0,9x+1-0,7y}=\frac{2,5+4,5x-4,5x}{0,7y+1-0,7y} = 2,5[/tex]
Explicație pas cu pas: