Question

Tính một cách hợp lí                                                                                                                       5/13. -3/10. -13/5

Answer 1

\(\dfrac{5}{13}.\dfrac{-3}{10}.\dfrac{-13}{5}\\=\dfrac{5}{13}.\dfrac{-13}{5}.\dfrac{-3}{10}\\ =-1.\dfrac{-3}{10}\\ =\dfrac{3}{10}\)

Answer 2

     5/13. -3/10. -13/5

=   5/13.-13/5.-3/10

=   (5/13.-13/5).-3/10

= -1.-3/10 

=3/10

 

Answer 3

\(\dfrac{5}{13}.\left(-\dfrac{3}{10}\right).\left(-\dfrac{13}{5}\right)\)

\(=\dfrac{5.\left(-3\right)}{13.10}.\left(-\dfrac{13}{5}\right)\)

\(=\dfrac{-3}{26}.\left(-\dfrac{13}{5}\right)\)

\(=\dfrac{-3.\left(-13\right)}{26.5}\)

\(=\dfrac{3}{10}\)

Answer 4

\(\dfrac{5}{13}\).\(\dfrac{-3}{10}\).\(\dfrac{-13}{5}\)

=\(\left(\dfrac{5}{13}.\dfrac{-13}{5}\right)\).\(\dfrac{-3}{10}\)

=\(\dfrac{-65}{65}\).\(\dfrac{-3}{10}\)

= -1.\(\dfrac{-3}{10}\)

=\(\dfrac{3}{10}\)