Đề bài

Tính: \(\dfrac{{ - 7}}{{12}} + \dfrac{5}{{12}}\);   \(\dfrac{{ - 8}}{{11}} + \dfrac{{ - 19}}{{11}}\)

Lời giải chi tiết

\(\dfrac{{ - 7}}{{12}} + \dfrac{5}{{12}} = \dfrac{{ - 7 + 5}}{{12}} = \dfrac{{ - 2}}{{12}} =  \dfrac{{ - 1}}{{6}}\) ;    \(\dfrac{{ - 8}}{{11}} + \dfrac{{ - 19}}{{11}} = \dfrac{{ - 8 + \left( { - 19} \right)}}{{11}} = \dfrac{{ - 27}}{{11}}\)