Câu 6: Thực hiện phép tính $\frac{19}{24} - \frac{1}{2} - \frac{3}{7} - \frac{7}{24}$ kết quả là
A. $-\frac{1}{3}$.
B. $-$.
C. $\frac{11}{24}$.
D. $\frac{4}{3}$.
Câu 7: Thực hiện phép tính $\frac{2}{5} + \frac{1}{6} - \frac{3}{4} = -\frac{2}{3}$ kết quả là
A. $-\frac{20}{3}$.
B. $\frac{20}{3}$.
C. $\frac{3}{20}$.
D. $-\frac{3}{20}$.
Câu 8: Thực hiện phép tính $\left( \frac{4}{3} - \frac{2}{3} \right) - \left( \frac{7}{10} - \frac{3}{10} \right) - \frac{1}{5} \left( \frac{8}{6} - \frac{7}{6} \right)$ kết quả là
A. $\frac{7}{30}$.
B. $\frac{2}{5}$.
C. $-\frac{2}{5}$.
D. $-\frac{3}{5}$.
Câu 9: Thực hiện phép tính $\frac{3}{15} - \frac{9}{17} - \frac{18}{14} + \frac{14}{17}$ kết quả là
A. $\frac{17}{81}$.
B. $-$.
C. $-\frac{17}{81}$.
D. $-\frac{7}{81}$.
Câu 10: Thực hiện phép tính $\left( \frac{13}{23} - \frac{1313}{2323} \right) \left( \frac{1313}{2323} - \frac{131313}{232323} \right) \left( \frac{1}{3} + \frac{7}{10} - \frac{10}{21} \right)$ kết quả là
A. $0$.
B. $2022$.
C. $1$.
D. $2$.
Câu 11:
Câu 6:
\(\dfrac{19}{24}-\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{7}{24}\)
\(=\dfrac{12}{24}-\dfrac{1}{2}-\dfrac{1}{3}=\dfrac{1}{2}-\dfrac{1}{2}-\dfrac{1}{3}=-\dfrac{1}{3}\)
=>Chọn A
Câu 7:
\(\dfrac{2}{5}+\dfrac{-1}{6}-\dfrac{3}{4}-\dfrac{-2}{3}\)
\(=\dfrac{24}{60}+\dfrac{-10}{60}-\dfrac{45}{60}+\dfrac{40}{60}\)
\(=\dfrac{24+40-55}{60}=\dfrac{9}{60}=\dfrac{3}{20}\)
=>Chọn C
Câu 8:
\(\left(\dfrac{4}{3}-\dfrac{2}{3}\right)\left(\dfrac{7}{10}-\dfrac{3}{10}\right)-\dfrac{1}{5}\left(\dfrac{8}{6}-\dfrac{7}{6}\right)\)
\(=\dfrac{2}{3}\cdot\dfrac{4}{10}-\dfrac{1}{5}\cdot\dfrac{1}{6}\)
\(=\dfrac{2}{3}\cdot\dfrac{2}{5}-\dfrac{1}{30}=\dfrac{4}{15}-\dfrac{1}{30}=\dfrac{7}{30}\)
=>Chọn A
Câu 9:
\(\dfrac{3}{15}\cdot\dfrac{5}{9}:\dfrac{-18}{17}\cdot\dfrac{14}{17}\)
\(=\dfrac{1}{5}\cdot\dfrac{5}{9}\cdot\dfrac{-17}{18}\cdot\dfrac{14}{17}\)
\(=\dfrac{1}{9}\cdot\dfrac{-7}{9}=\dfrac{-7}{81}\)
=>Chọn D
Câu 10:
\(\left(\dfrac{13}{23}+\dfrac{1313}{2323}-\dfrac{131313}{232323}\right)\left(\dfrac{1}{3}+\dfrac{1}{7}-\dfrac{10}{21}\right)\)
\(=\left(\dfrac{13}{23}+\dfrac{13}{23}-\dfrac{13}{23}\right)\left(\dfrac{7}{21}+\dfrac{3}{21}-\dfrac{10}{21}\right)\)
\(=\dfrac{13}{23}\cdot0=0\)
=>Chọn A
Câu 11: \(\left(\dfrac{4}{5}+\dfrac{1}{2}\right)\left(\dfrac{3}{15}-\dfrac{8}{13}\right)\)
\(=\left(\dfrac{8}{10}+\dfrac{5}{10}\right)\left(\dfrac{1}{5}-\dfrac{8}{13}\right)\)
\(=\dfrac{13}{10}\left(\dfrac{13}{65}-\dfrac{40}{65}\right)=\dfrac{13}{10}\cdot\dfrac{-27}{65}=\dfrac{-27}{50}\)
=>Chọn C
Câu 12:
\(\left(-\dfrac{3}{4}+\dfrac{7}{3}\right):\left(\dfrac{2}{9}-\dfrac{5}{2}\right)\)
\(=\left(-\dfrac{9}{12}+\dfrac{28}{12}\right):\left(\dfrac{4}{18}-\dfrac{45}{18}\right)\)
\(=\dfrac{19}{12}\cdot\dfrac{18}{-41}\)
\(=\dfrac{-19}{41}\cdot\dfrac{3}{2}=\dfrac{-57}{82}\)
=>Chọn B
