let x be the dimes and y the quarters. So we get
[tex]\begin{gathered} \begin{cases}x+y=250 \\ 0.1x+0.25y=39.25\end{cases}\rightarrow x=250-y\rightarrow \\ 0.1(250-y)+0.25y=39.25 \\ 25-0.1y+0.25y=39.25 \\ 25+0.15y=39.25 \\ 0.15y=14.25 \\ y=\frac{14.25}{0.15}=95 \end{gathered}[/tex]having that there are 95 quarters. We get that:
[tex]x=250-95=155[/tex]there are 155 dimes
