\(\left(\frac{\frac{17}{24}.9\frac{1}{2}-3\frac{1}{4}.\frac{17}{24}}{3\frac{1}{2}.2\frac{13}{36}+2\frac{13}{36}.2\frac{3}{4}}-\frac{1}{2}\right)^{-2}\)
\(=\left(\frac{\frac{17}{24}.\left(9\frac{1}{2}-3\frac{1}{4}\right)}{2\frac{13}{36}.\left(3\frac{1}{2}+2\frac{3}{4}\right)}-\frac{1}{2}\right)^{-2}\)
\(=\left(\frac{\frac{17}{24}.\left(\frac{19}{2}-\frac{13}{4}\right)}{\frac{85}{36}.\left(\frac{7}{2}+\frac{11}{4}\right)}-\frac{1}{2}\right)^{-2}\)
\(=\left(\frac{\frac{17}{24}.\frac{19.2-13}{4}}{\frac{85}{36}.\frac{7.2+11}{4}}-\frac{1}{2}\right)^{-2}\)
\(=\left(\frac{\frac{17}{24}.\frac{25}{4}}{\frac{85}{36}.\frac{25}{4}}-\frac{1}{2}\right)^{-2}\)
\(=\left(\frac{17}{24}:\frac{85}{36}-\frac{1}{2}\right)^{-2}\)
\(=\left(\frac{17}{24}.\frac{36}{85}-\frac{1}{2}\right)^{-2}\)
\(=\left(\frac{3}{10}-\frac{1}{2}\right)^{-2}\)
\(=\left(\frac{3-5}{10}\right)^{-2}\)
\(=\left(\frac{-1}{5}\right)^{-2}\)
\(=\frac{1}{\left(-\frac{1}{5}\right)^2}=\frac{1}{\frac{\left(-1\right)^2}{5^2}}=\frac{1}{\frac{1}{25}}=25\)
