Cho \[M = \left( {\frac + \frac{{ - 16}}{7}} \right) + \left( {\frac + \frac} \right) + \frac{9}\] và \[N = \frac{1}{2} + \frac{{ - 1}}{5} + \frac{{ - 5}}{7} + \frac{1}{6} + \frac{{ - 3}} + \frac{1}{3} + \frac{1}\]. Chọn câu đúng

Trả lời:

\[M = \left( {\frac + \frac{{ - 16}}{7}} \right) + \left( {\frac + \frac} \right) + \frac{9}\]

\[M = \frac + \frac{{ - 16}}{7} + \frac + \frac + \frac{9}\]

\[M = \left( {\frac + \frac} \right) + \left( {\frac + + \frac{9}} \right) + \frac{{ - 16}}{7}\]

\[M = 1 + 1 + \frac{{ - 16}}{7}\]

\[M = 2 + \frac{{ - 16}}{7}\]

\[M = \frac{{ - 2}}{7}\]

\[N = \frac{1}{2} + \frac{{ - 1}}{5} + \frac{{ - 5}}{7} + \frac{1}{6} + \frac{{ - 3}} + \frac{1}{3} + \frac{1}\]

\[N = \left( {\frac{1}{2} + \frac{1}{6} + \frac{1}{3}} \right) + \left( {\frac{{ - 1}}{5} + \frac{{ - 5}}{7} + \frac{{ - 3}}} \right) + \frac{1}\]

\[N = \frac{6} + \frac{{\left( { - 7} \right) + \left( { - 25} \right) + \left( { - 3} \right)}} + \frac{1}\]

\[N = 1 + \left( { - 1} \right) + \frac{1}\]

\[N = \frac{1}\]

Đáp án cần chọn là: D