Question

[thùy phạm]

1) Tính : a) \(\left(\dfrac{-5}{11}\right)\) .\(\dfrac{7}{15}\) . \(\left(\dfrac{11}{-5}\right)\) .(-30) b) \(\left(\dfrac{11}{12}:\dfrac{33}{16}\right)\). \(\dfrac{3}{5}\) c) \(\dfrac{-7}{15}\).\(\dfrac{5}{8}\).\(\dfrac{15}{-7}\). (-16) d) \(\left(-\dfrac{1}{2}\right)\). \(3\dfrac{1}{5}\)+ \(\left(-\dfrac{1}{2}\right)\).\(-2\dfrac{1}{5}\)

Answer 1

[Miinhhoa]

a, \(\left(\dfrac{-5}{11}\right).\dfrac{7}{15}.\left(\dfrac{11}{-5}\right).\left(-30\right)=\dfrac{-5}{11}.\dfrac{7}{15}.\dfrac{-11}{5}.\dfrac{-30}{1}\)= ( - 14 )

b, \(\left(\dfrac{11}{12}:\dfrac{33}{16}\right).\dfrac{3}{5}=\dfrac{11}{12}.\dfrac{16}{33}.\dfrac{3}{5}=\dfrac{1.4.3}{3.3.5}=\dfrac{4}{15}\)

c, \(\dfrac{-7}{15}.\dfrac{5}{8}.\dfrac{15}{-7}.\left(-16\right)=\dfrac{-7}{15}.\dfrac{5}{8}.\dfrac{-15}{7}.\dfrac{-16}{1}\)

\(\dfrac{-1.5.-1.-2}{1.1.1.1}=\left(-10\right)\)

d,\(\left(\dfrac{-1}{2}\right).3\dfrac{1}{5}+\left(\dfrac{-1}{2}\right).-2\dfrac{1}{5}=\left(\dfrac{-1}{2}\right).\left[\dfrac{16}{5}+\left(\dfrac{-11}{5}\right)\right]\)

= \(\left(\dfrac{-1}{2}\right).1=\dfrac{-1}{2}\)

Answer 2

[Kẹo Kẹo Mút]

a) (-5/11.11/-5).7/15

=1.7/15=7/15

b)(11/12:33/16).3/5

=(11/12.16/33).3/5

=4/9.3/5=4/15

c)(-7/15.15/-7).5/8

=1.5/8=5/8

d)(-1/2).(16/5.-11/5)

=-1/2.1=-1/2

xg r đó