Câu hỏi:
Tính: \(A = \left( {17\frac{{29}}{{31}} – 3\frac{7}{8} + 17\frac{{51}}{{59}}} \right) – \left( {2\frac{{29}}{{31}} + 7\frac{{51}}{{59}} – 4} \right)\)
-
A.
\({25\frac{3}{8} }\) -
B.
\({25\frac{1}{8} }\) -
C.
\({15\frac{3}{8} }\) -
D.
\({15\frac{1}{8} }\)
Lời giải tham khảo:
Đáp án đúng: B
Ta có:
\(\begin{array}{*{20}{l}} {A = \left( {17\frac{{29}}{{31}} – 3\frac{7}{8} + 17\frac{{51}}{{59}}} \right) – \left( {2\frac{{29}}{{31}} + 7\frac{{51}}{{59}} – 4} \right)}\\ { = 17\frac{{29}}{{31}} – 3\frac{7}{8} + 17\frac{{51}}{{59}} – 2\frac{{29}}{{31}} – 7\frac{{51}}{{59}} + 4}\\ { = \left( {17\frac{{29}}{{31}} – 2\frac{{29}}{{31}}} \right) + \left( {17\frac{{51}}{{59}} – 7\frac{{51}}{{59}}} \right) – 3\frac{7}{8} + 4}\\ { = 15 + 10 – \frac{{31}}{8} + 4 = \frac{{201}}{8} = 25\frac{1}{8}} \end{array}\)
Trả lời