Question

quy đồng mẫu số

-3/5;-5/6;3     -1;-9/7;-19/15

Answer 1

a: MSC=30

\(-\dfrac{3}{5}=\dfrac{-3\cdot6}{5\cdot6}=\dfrac{-18}{30}\)

\(\dfrac{-5}{6}=\dfrac{-5\cdot5}{6\cdot5}=\dfrac{-25}{30}\)

\(3=\dfrac{3\cdot30}{1\cdot30}=\dfrac{90}{30}\)

b: MSC=105

\(-1=\dfrac{-1\cdot105}{105}=\dfrac{-105}{105}\)

\(\dfrac{-9}{7}=\dfrac{-9\cdot15}{7\cdot15}=\dfrac{-135}{105}\)

\(\dfrac{-19}{15}=\dfrac{-19\cdot7}{15\cdot7}=\dfrac{-133}{105}\)