Đáp án:
$\displaystyle \begin{array}{{>{\displaystyle}l}} b.\ 1;\ b.\ \frac{1}{6} ;\ c.\ \frac{4}{3}\\ d.\ \frac{-8}{5} ;\ e.\ \frac{-1}{3} \end{array}$
Giải thích các bước giải:
$\displaystyle \begin{array}{{>{\displaystyle}l}} b.\ \frac{8^{2} .8^{3}}{2^{8} .2^{7}} =\frac{2^{6} .2^{9}}{2^{8} .2^{7}} =1\\ b.\ \frac{2^{5} .6^{3}}{8^{3} .9^{2}} =\frac{2^{5} .2^{3} .3^{3}}{2^{9} .3^{4}} =\frac{1}{6}\\ c.\ \frac{9^{8} .8^{6}}{16^{4} .3^{17}} =\frac{3^{16} .2^{18}}{2^{16} .3^{17}} =\frac{4}{3}\\ d.\ \frac{16^{11} .( -5)^{40}}{( -10)^{41}} =\frac{2^{44} .5^{40}}{-5^{41} .2^{41}} =\frac{-2^{3}}{5} =\frac{-8}{5}\\ e.\ \frac{4^{5} .9^{4} -2.6^{9}}{2^{10} .3^{8} +6^{8} .20} =\frac{2^{10} .3^{8} -2.2^{9} .3^{9}}{2^{10} .3^{8} +2^{8} .3^{8} +2^{2} .5}\\ =\frac{2^{10} .3^{8} .( 1-3)}{2^{10} .3^{8} .( 1+5)} =\frac{-2}{6} =-\frac{1}{3} \end{array}$
