a ) \(\frac{-5}{9}:\frac{-7}{18}+1\frac{2}{7}\)
\(=\frac{-5}{9}.-\frac{18}{7}+\frac{9}{7}\)
\(=\frac{-5.-18}{9.7}+\frac{9}{7}\)
\(=\frac{10}{7}+\frac{9}{7}\)
\(=\frac{10+9}{7}\)
\(=\frac{19}{7}\)
\(\frac{2^{27}\times9^4}{6^9\times8^5}=\frac{2^{27}\times\left(3^2\right)^4}{\left(2\times3\right)^9\times\left(2^3\right)^5}=\frac{2^{27}\times3^8}{2^9\times3^9\times2^{15}}=\frac{2^3}{3}=\frac{8}{3}\)
\(\sqrt{13^2}-5^2+\sqrt{3^2+4^2}-\sqrt{\left(-7\right)^2}=13-25+\sqrt{9+16}-\sqrt{49}=13-25+5-7=-14\)
Mấy câu này bạn bấm máy tính là ra thui