Question

1 Tính:

a)\(\dfrac{\dfrac{7}{10}+\dfrac{3}{5}}{\dfrac{7}{10}+\dfrac{1}{2}}\) b)\(\dfrac{6-\dfrac{1}{\dfrac{1}{2}-\dfrac{1}{3}}}{6+\dfrac{1}{\dfrac{1}{2}-\dfrac{1}{3}}}\)

Answer 1

a) \(\dfrac{\dfrac{7}{10}+\dfrac{3}{5}}{\dfrac{7}{10}+\dfrac{1}{2}}\) = (\(\dfrac{7}{10}+\dfrac{3}{5}\) ) : ( \(\dfrac{7}{10}+\dfrac{1}{2}\) )

= \(\dfrac{7+6}{10}\) : \(\dfrac{7+5}{10}\)

= \(\dfrac{13}{10}:\dfrac{12}{10}\)

= \(\dfrac{13}{10}.\dfrac{10}{12}\) =\(\dfrac{13}{12}\)

b) \(\dfrac{6-\dfrac{1}{\dfrac{1}{2}-\dfrac{1}{3}}}{6+\dfrac{1}{\dfrac{1}{2}-\dfrac{1}{3}}}\)

= ( 6 - \(\dfrac{1}{\dfrac{1}{2}-\dfrac{1}{3}}\) ) : ( 6 + \(\dfrac{1}{\dfrac{1}{2}-\dfrac{1}{3}}\) )

= ( 6 - \(\dfrac{1}{\dfrac{1}{6}}\) ) : ( 6 + \(\dfrac{1}{\dfrac{1}{6}}\) )

= ( 6 - 6 ) : (6 + 6) = \(\dfrac{0}{12}\) =0