Question

quy đồng mẫu số cấc phân số sau 

a) 3/4 ; 1/-9 ; -5/8

b) 1/-7 ; -1/-8 ; 3/4

c 1/3 ; -1/5 ; 1/-10

Answer 1

a: 3/4=54/72

-1/9=-8/72

-5/8=-45/72

b: -1/7=-8/56

1/8=7/56

3/4=42/56

c: 1/3=10/30

-1/5=-6/30

-1/10=-3/30

Answer 2

a)\(\dfrac{3}{4}=\dfrac{3.18}{4.18}=\dfrac{54}{72}\)

\(\dfrac{1}{-9}=\dfrac{-1}{9}=\dfrac{-1.8}{9.8}=\dfrac{-8}{72}\)

\(\dfrac{-5}{8}=\dfrac{-5.9}{8.9}=\dfrac{-45}{72}\)

b)\(\dfrac{1}{-7}=\dfrac{-1}{7}=\dfrac{-1.8}{7.8}=\dfrac{-8}{56}\)

\(\dfrac{-1}{-8}=\dfrac{1}{8}=\dfrac{1.7}{8.7}=\dfrac{7}{56}\)

\(\dfrac{3}{4}=\dfrac{3.14}{4.14}=\dfrac{42}{56}\)

c)\(\dfrac{1}{3}=\dfrac{1.10}{3.10}=\dfrac{10}{30}\)

\(\dfrac{-1}{5}=\dfrac{-1.6}{5.6}=\dfrac{-6}{30}\)

\(\dfrac{1}{-10}=\dfrac{-1}{10}=\dfrac{-1.3}{10.3}=\dfrac{-3}{30}\)