\(\eqalign{
& a)\,\,3,5.\left( { - 1{2 \over 5}} \right) \cr
& = 3,5.\left( { - {7 \over 5}} \right) = {{35} \over {10}}.{{ - 7} \over 5} \cr
& = {7 \over 2}.{{ - 7} \over 5} = {{7.( - 7)} \over {2.5}} = {{ - 49} \over {10}} \cr
& b)\,\,{{ - 5} \over {23}}:( - 2) = {{ - 5} \over {23}}.{{ - 1} \over 2} \cr
& = {{( - 5).( - 1)} \over {23.2}} = {5 \over {46}} \cr} \)
