b) \(\dfrac{\left(0,8\right)^5}{\left(0,4\right)^6}\)
\(=\dfrac{\left(0,8\right)^5}{\left(0.4\right)^5\cdot0,4}\)
\(=\left(\dfrac{0,8}{0,4}\right)^5\cdot\dfrac{1}{0,4}\)
\(=2^5\cdot\dfrac{5}{2}\)
\(=\dfrac{2^5\cdot5}{2}\)
\(=2^4\cdot5\)
\(=80\)
c) \(\dfrac{2^{15}\cdot9^4}{6^6\cdot8^3}\)
\(=\dfrac{2^{15}\cdot\left(3^2\right)^4}{2^6\cdot3^6\cdot\left(2^3\right)^3}\)
\(=\dfrac{2^{15}\cdot3^8}{2^{15}\cdot3^6}\)
\(=\dfrac{3^2}{1}\)
\(=9\)
c) 2^15.9^466.83=2^15.3^8/2^6.3^6.2^9=3^2/1=9
dấu này / là phần nha