Question

1 . tính bằng cách hợp lí :

a . ( 5/6 + 3/4 - 0,9 ) : ( 5/6 - 3/4 + 0,9 )

b . ( 13 7/12 + 4 3/10 ) - 8 7/12

c . 31 4/17 - 8 5/13 - 11 8/13

Answer 1

a: \(=\left(\dfrac{5}{6}+\dfrac{3}{4}-\dfrac{9}{10}\right):\left(\dfrac{5}{6}-\dfrac{3}{4}+\dfrac{9}{10}\right)\)

\(=\dfrac{50+45-54}{60}:\dfrac{50-45+54}{60}\)

\(=\dfrac{41}{59}\)

b: \(=13+\dfrac{7}{12}+4+\dfrac{3}{10}-8-\dfrac{7}{10}=\dfrac{3}{10}+1=\dfrac{13}{10}\)

c: \(=31+\dfrac{4}{17}-8-\dfrac{5}{13}-11-\dfrac{8}{13}\)

\(=11+\dfrac{4}{17}=\dfrac{191}{17}\)