a) Ta có: \(25\cdot\left(\frac{5}{2}\right)^{-2}\cdot\left(-2^{-3}\right)^{-1}\)
\(=25\cdot\frac{4}{25}\cdot\left(-8\right)\)
\(=4\cdot\left(-8\right)=-32\)
b) Ta có: \(\left(5^{-5}\right)^{-1}\cdot\left(\frac{1}{2}\right)^{-2}\cdot\left(\frac{1}{10}\right)^5\)
\(=3125\cdot4\cdot\frac{1}{100000}\)
\(=\frac{1}{8}\)