Đề bài

Tính một cách hợp lí

a) $\frac{{11}}{4}.\frac{{ - 5}}{9}.\frac{8}{{33}};$

b) $\frac{{ - 5}}{6}.\frac{4}{{19}} + \frac{{ - 7}}{{12}}.\frac{4}{{19}} - \frac{{40}}{{57}}$

c) $\left( {\frac{{23}}{{41}} - \frac{{15}}{{82}}} \right).\frac{{41}}{{15}}$

d) $9\left( {\frac{{151515}}{{171717}} - \frac{{131313}}{{181818}}} \right);$

e) $\frac{{ - 13}}{8}.\left( {\frac{8}{{13}} + \frac{{32}}{{28}}} \right) - \frac{{15}}{7}$

g) $\frac{{{2^2}}}{{1.3}}.\frac{{{3^2}}}{{2.4}}.\frac{{{4^2}}}{{3.5}}.\frac{{{5^2}}}{{4.6}}.\frac{{{6^2}}}{{5.7}}$