11: \(=\dfrac{3}{64}-\dfrac{1}{64}-1=\dfrac{1}{32}-1=-\dfrac{31}{32}\)
12: \(=\dfrac{4}{25}-\left(\dfrac{1}{2}+\dfrac{9}{10}\right)\cdot\dfrac{25}{7}\)
\(=\dfrac{4}{25}-\dfrac{5+9}{10}\cdot\dfrac{25}{7}\)
\(=\dfrac{4}{25}-\dfrac{7}{5}\cdot\dfrac{25}{7}=\dfrac{4}{25}-5=-\dfrac{121}{25}\)
13: \(=\dfrac{2}{3}+\dfrac{1}{4}\cdot\dfrac{4}{3}-1=\dfrac{2}{3}+\dfrac{1}{3}-1=0\)