[tex]\bold{1)} \ \frac{6}{8}^{(2} = \frac{3}{4} =\boxed{0,75}. \\ \\ \bold{2)} \ 12 \% \ din \ 45= \frac{12}{100} \cdot45=0,12 \cdot45=\boxed{5,4}. \\ \\ \bold{3)} \ \frac{x}{12} = \frac{15}{10} \\ \Rightarrow x= \frac{15}{10} \cdot12 \\ x=1,5 \cdot12 \\ \boxed{x=18}.[/tex]
