Question

Bài 2 trang 131 trên a) 3/4 - 2/7 ; b) 3/8 - 5/16 ; c) 7/5 - 2/3; d) 31/36 - 5/6

Answer 1

\(a,\dfrac{3}{4}-\dfrac{2}{7}=\dfrac{13}{28}\\ b,\dfrac{3}{8}-\dfrac{5}{16}=\dfrac{1}{16}\\ c,\dfrac{7}{5}-\dfrac{2}{3}=\dfrac{11}{15}\\ d,\dfrac{31}{36}-\dfrac{5}{6}=\dfrac{1}{36}\)

Answer 2

\(a,\dfrac{3}{4}-\dfrac{2}{7}=\dfrac{21}{28}-\dfrac{8}{28}=\dfrac{13}{28}\)

\(b,\dfrac{3}{8}-\dfrac{5}{16}=\dfrac{6}{16}-\dfrac{5}{16}=\dfrac{1}{16}\)

\(c,\dfrac{7}{5}-\dfrac{2}{3}=\dfrac{21}{15}-\dfrac{10}{15}=\dfrac{11}{15}\)

\(d,\dfrac{31}{36}-\dfrac{5}{6}=\dfrac{31}{36}-\dfrac{30}{36}=\dfrac{1}{36}\)

Answer 3

a) \(\dfrac{3}{4}-\dfrac{2}{7}=\dfrac{21-8}{28}=\dfrac{13}{28}\) 

b)\(\dfrac{3}{8}-\dfrac{5}{16}=\dfrac{6-5}{16}=\dfrac{1}{16}\) 

c)\(\dfrac{7}{5}-\dfrac{2}{3}=\dfrac{21-10}{15}=\dfrac{11}{15}\) 

d)\(\dfrac{31}{36}-\dfrac{5}{6}=\dfrac{31-30}{36}=\dfrac{1}{36}\)

Answer 4

`a) 3/4 - 2/7 =21/28 - 8/28 = 13/28`

`b) 3/8 - 5/16 = 6/16 -5/16 = 1/16`

` c) 7/5 - 2/3= 21/15 - 10/15 = 11/15`

`d) 31/36 - 5/6 = 31/36 - 30/36 = 1/36`

Answer 5

a) \(\dfrac{3}{4}\) - \(\dfrac{2}{7}\) = \(\dfrac{21}{28}\) - \(\dfrac{8}{28}\) = \(\dfrac{13}{28}\)                b) \(\dfrac{3}{8}\) - \(\dfrac{5}{16}\) = \(\dfrac{6}{16}\) - \(\dfrac{5}{16}\) = \(\dfrac{1}{16}\)

c) \(\dfrac{7}{5}\) - \(\dfrac{2}{3}\) = \(\dfrac{21}{15}\) - \(\dfrac{10}{15}\) =  \(\dfrac{11}{15}\)               d) \(\dfrac{31}{36}\) - \(\dfrac{5}{6}\) = \(\dfrac{31}{36}\) - \(\dfrac{30}{36}\) = \(\dfrac{1}{36}\)