(-5/11).7/15.(11/-5).(-30) (11/12:33/16).3/5 (-5/9).3/11+(-13/18).3/11

Đáp án:

Giải thích các bước giải: \[\begin{array}{l}\left( { - 5/11} \right).7/15.\left( {11/ - 5} \right).\left( { - 30} \right)\\ = \frac{{ - 5}}{{11}}.\frac{7}{{15}}.\frac{{11}}{{ - 5}}.30\\ = \frac{{17}}{{15}}.30\\ = 34\end{array}\] \[\begin{array}{l}\left( {11/12:33/16} \right).3/5\\ = \left( {\frac{{11}}{{12}}:\frac{{33}}{{16}}} \right).\frac{3}{5}\\ = \frac{{11}}{{12}}.\frac{{16}}{{11}}.\frac{3}{5}\\ = \frac{{11}}{{3.4}}.\frac{{4.4}}{{11}}.\frac{3}{5}\\ = \frac{4}{5}\end{array}\] \[\begin{array}{l}\left( { - 5/9} \right).3/11 + \left( { - 13/18} \right).3/11\\ = \frac{{ - 5}}{9}.\frac{3}{{11}} + \left( {\frac{{ - 13}}{{18}}} \right).\frac{3}{{11}}\\ = \frac{3}{{11}}\left( {\frac{{ - 5}}{9} - \frac{{13}}{{18}}} \right)\\ = \frac{3}{{11}}.\frac{{ - 23}}{{18}}\\ = \frac{{ - 69}}{{198}}\\ = - \frac{{23}}{{66}}\end{array}\]