Question

thực hiện phép tính

\(\dfrac{5}{12}+\dfrac{-7}{12}\)

\(\dfrac{1}{2}+\dfrac{-2}{3}\)

\(\dfrac{3}{5}-\dfrac{4}{3}\)

\(\dfrac{-15}{14}.\dfrac{21}{20}\)

Answer 1

\(\dfrac{5}{12}+\dfrac{-7}{12}=\dfrac{-2}{12}=\dfrac{-1}{6}\)

\(\dfrac{1}{2}+\dfrac{-2}{3}=\dfrac{3}{6}+\dfrac{-4}{6}=\dfrac{-1}{6}\)

\(\dfrac{3}{5}-\dfrac{4}{3}=\dfrac{9}{15}-\dfrac{20}{15}=\dfrac{-11}{15}\)

\(\dfrac{-15}{14}.\dfrac{21}{20}=\dfrac{-315}{280}=\dfrac{-9}{8}\)

Answer 2

\(\dfrac{-1}{6}\)

\(\dfrac{-1}{6}\)

\(\dfrac{-11}{15}\)

\(\dfrac{-9}{8}\)