Question

Các bạn ơi giúp mềnh vứi

Answer 1

\(a.\dfrac{2}{3}+\dfrac{5}{4}=\dfrac{8+15}{12}=\dfrac{23}{12}.\\ b.\dfrac{3}{5}+\dfrac{9}{8}=\dfrac{24+45}{40}=\dfrac{69}{40}.\\ c.\dfrac{3}{4}-\dfrac{2}{7}=\dfrac{21-8}{28}=\dfrac{13}{28}.\\ d.\dfrac{11}{5}-\dfrac{4}{3}=\dfrac{33-20}{15}=\dfrac{13}{15}.\)

Answer 2

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Answer 3

Các bạn có thể làm câu nào cũng được nhé

Answer 4

Bài 4:

a) 12/17 + 19/17 + 8/17

= ( 12/17 + 8/17 ) + 19/17

= 20/17 + 19/17

= 39/17

b) 2/5 + 7/12 + 13/12

= 2/5 + ( 7/12 + 13/12 )

= 2/5 + 20/12

= 124/60

= 31/20