1 B
2 A
3 B
4 A
5C
6 C
7 A
8A
phần II
\(\dfrac{2}{3}+\dfrac{1}{8}+\dfrac{5}{12}=\dfrac{16}{24}+\dfrac{3}{24}+\dfrac{10}{24}=\dfrac{29}{24}=1\dfrac{5}{4}\)
\(\dfrac{6}{5}-\dfrac{1}{15}-\dfrac{7}{9}=\dfrac{108}{90}-\dfrac{6}{90}-\dfrac{70}{90}=\dfrac{32}{90}=\dfrac{16}{45}\)