Bài 1:
\(a,\dfrac{-8}{18}-\dfrac{15}{27}=-\dfrac{4}{9}-\dfrac{5}{9}=\dfrac{-4-5}{9}=\dfrac{-9}{9}=-1\\ b,\dfrac{-3}{4}.\dfrac{12}{-5}\left(-\dfrac{25}{6}\right)=\dfrac{9}{5}.\left(-\dfrac{25}{6}\right)=-\dfrac{15}{2}\\ c,\left(\dfrac{-2}{3}+\dfrac{3}{13}\right):\dfrac{7}{8}+\left(\dfrac{-1}{3}+\dfrac{10}{13}\right):\dfrac{7}{8}=\left(\dfrac{-2}{3}+\dfrac{3}{13}\right).\dfrac{8}{7}+\left(\dfrac{-1}{3}+\dfrac{10}{13}\right).\dfrac{8}{7}=\left(-\dfrac{2}{3}+\dfrac{3}{13}+-\dfrac{1}{3}+\dfrac{10}{13}\right).\dfrac{8}{7}=\left(-1+1\right).\dfrac{8}{7}=0.\dfrac{8}{7}=0\)
\(d,4.2^3:\left(2^7.\dfrac{1}{32}\right)=2^2.2^3:\left(2^7.\dfrac{1}{2^5}\right)=2^5:2^2=2^3=8\\ e,\left(\dfrac{-1}{5}\right)^2+\dfrac{1}{5}-2.\left(-\dfrac{1}{2}\right)^3-\dfrac{1}{2}=\dfrac{1}{25}+\dfrac{1}{5}-2.\left(\dfrac{-1}{8}\right)-\dfrac{1}{2}=\dfrac{1}{25}+\dfrac{1}{5}+\dfrac{1}{4}-\dfrac{1}{2}=-\dfrac{1}{100}\)
\(f,\dfrac{\left(-1\right)^3}{15}+\left(\dfrac{-2}{3}\right)^2:2\dfrac{2}{3}-\left|-\dfrac{5}{6}\right|=\dfrac{-1}{15}+\dfrac{4}{9}:\dfrac{8}{3}-\dfrac{5}{6}=\dfrac{-1}{15}+\dfrac{4}{9}.\dfrac{3}{8}-\dfrac{5}{6}=\dfrac{-1}{15}+\dfrac{1}{6}-\dfrac{5}{6}=-\dfrac{1}{15}-\dfrac{2}{3}=-\dfrac{11}{15}\)
\(g,\sqrt{64}+2\sqrt{\left(-3\right)^2}-8\sqrt{\dfrac{25}{16}}=8+2.3-8.\dfrac{5}{4}=8+6-10=4\\ h,\dfrac{32^3.9^5}{8^3.6^6}=\dfrac{\left(2^5\right)^3.\left(3^2\right)^5}{\left(2^3\right)^3.\left(2.3\right)^6}=\dfrac{2^{15}.3^{10}}{2^9.2^6.3^6}=\dfrac{2^{15}.3^{10}}{2^{15}.3^6}=3^4=81\)
