Tính hợp lý

B

- Hướng dẫn giải

Đáp án B

$$\begin{gathered} A=\left(17\frac{29}{31}-3\frac{7}{8}+17\frac{51}{59}\right)-\left(2\frac{29}{31}+7\frac{51}{59}-4\right) \\ =17\frac{29}{31}-3\frac{7}{8}+17\frac{51}{59}-2\frac{29}{31}-7\frac{51}{59}+4 \\ =\left(17\frac{29}{31}-2\frac{29}{31}\right)-\left(17\frac{51}{59}-7\frac{51}{59}+4\right) \\ =15+10-\frac{31}{8}+4=\frac{201}{4}=25\frac{1}{8} \end{gathered}$$