Question

tính

a. 1/2 . ( 4/3 + 2/5 ) - 3/4 . ( 8/9 + 13/3 )

b. 1/5 : 1/10 - 1/3 . ( 6/5 - 9/4 )

c. -3/4 . ( 20/9 - 8/15 ) - 5/3 . 9/10

p/s: mình đang cần gấp, bạn nào giúp mình cái nhé

Answer 1

Tính

a) \(\dfrac{1}{2}\) . ( \(\dfrac{4}{3}\) + \(\dfrac{2}{5}\) ) - \(\dfrac{3}{4}\) . ( \(\dfrac{8}{9}\) + \(\dfrac{13}{3}\) )

= \(\dfrac{1}{2}\) . \(\dfrac{8}{15}\) - \(\dfrac{3}{4}\) . \(\dfrac{47}{9}\)

= \(\dfrac{4}{15}\) - \(\dfrac{47}{12}\)

= \(\dfrac{-73}{20}\)

b) \(\dfrac{1}{5}\) : \(\dfrac{1}{10}\) - \(\dfrac{1}{3}\) . ( \(\dfrac{6}{5}\)-\(\dfrac{9}{4}\) )

= 2 - \(\dfrac{1}{3}\) . \(\dfrac{-21}{20}\)

= 2 - \(\dfrac{-7}{20}\)

= \(\dfrac{47}{20}\)

c) \(\dfrac{-3}{4}\) . ( \(\dfrac{20}{9}\) - \(\dfrac{8}{15}\) ) - \(\dfrac{5}{3}\) . \(\dfrac{9}{10}\)

= \(\dfrac{-3}{4}\) . \(\dfrac{76}{45}\) - \(\dfrac{3}{2}\)

= \(\dfrac{-19}{15}\) - \(\dfrac{3}{2}\)

= \(\dfrac{-7}{30}\)