a) \(9,2\cdot2\frac{1}{2}-\left(2\cdot0,125-1\frac{5}{12}\right):\frac{1}{4}\)
\(=23-\left(0,25-\frac{17}{12}\right):\frac{1}{4}\)
\(=23-\left(-\frac{7}{6}\right):\frac{1}{4}\)
\(=23-\left(-\frac{14}{3}\right)\)
\(=\frac{83}{3}\)
b) \(\frac{\sqrt{3^2}-\sqrt{39^2}}{\sqrt{59-10-\sqrt{91^2}}}\)
\(=\frac{3-39}{\sqrt{59-10-91}}\)
\(=\frac{-36}{\sqrt{-42}}\)
Vì -42 < 0 \(\Leftrightarrow\)Biểu thức không tồn tại
c) \(\frac{5}{18}-1,456:\frac{7}{25}+4,5\cdot\frac{4}{5}\)
\(=\frac{5}{18}-\frac{26}{5}+\frac{18}{5}\)
\(=\frac{5}{18}-\frac{8}{5}\)
\(=\frac{-119}{90}\)