1,11 + 0,19 – 1.3 x 2 _____________________ – ( 1/2 + 1/3) : 2 2,06 + 0,54

Đáp án:

$\begin{array}{l}
\dfrac{{1,11 + 0,19 – 1,3.2}}{{2,06 + 0,54}} – \left( {\dfrac{1}{2} + \dfrac{1}{3}} \right):2\\
 = \dfrac{{1,3 – 1,3.2}}{{2,6}} – \left( {\dfrac{3}{6} + \dfrac{2}{6}} \right):2\\
 = \dfrac{{1,3.\left( {1 – 2} \right)}}{{1,3.2}} – \dfrac{5}{6}.\dfrac{1}{2}\\
 = \dfrac{{ – 1}}{2} – \dfrac{5}{6}.\dfrac{1}{2}\\
 = \dfrac{1}{2}.\left( { – 1 – \dfrac{5}{6}} \right)\\
 = \dfrac{1}{2}.\left( {\dfrac{{ – 11}}{6}} \right)\\
 = \dfrac{{ – 11}}{{12}}
\end{array}$