Question

1.thực hiện phép tính:

a, 24-{12-[(-10)-(-2)]}

b,2/3+1/3.(-2/3+5/6):2/3

2.tính nhanh:

a,\(-\frac{2}{5}+\left(-\frac{5}{9}+\frac{2}{5}\right)\)

b, 17/13-(4/13 - 11)

c,3/5.18/17+3/5.9/17-3/5.10/17

GIÚP IK GIÚP TUI VỚI! PLEASE

Answer 1

1/

a, 24 - {12 -[(-10)-(-2)]}

=24-{12-(-8)}

=24-20

=4

Answer 2

b,\(\frac{2}{3}\)+\(\frac{1}{3}\).(\(\frac{-2}{3}\)+\(\frac{5}{6}\)):\(\frac{2}{3}\)

=\(\frac{2}{3}\)+\(\frac{1}{3}\).(\(\frac{-4}{6}\)+\(\frac{5}{6}\)):\(\frac{2}{3}\)

=\(\frac{2}{3}\)+\(\frac{1}{3}\).\(\frac{1}{6}\).\(\frac{3}{2}\)

=\(\frac{2}{3}\)+\(\frac{1}{18}\).\(\frac{3}{2}\)

=\(\frac{2}{3}\)+\(\frac{1}{6}\).\(\frac{1}{2}\)

=\(\frac{2}{3}\)+\(\frac{1}{12}\)

=\(\frac{8}{12}\)+\(\frac{1}{12}\)

=\(\frac{9}{12}\)=\(\frac{3}{4}\)

Answer 3

2/

a,\(\frac{-2}{5}\)+(\(\frac{-5}{9}\)+\(\frac{2}{5}\))

=\(\frac{-2}{5}\)+\(\frac{-5}{9}\)+\(\frac{2}{5}\)

=(\(\frac{-2}{5}\)+\(\frac{2}{5}\))+\(\frac{-5}{9}\)

=         0+\(\frac{-5}{9}\)

=          \(\frac{-5}{9}\)

Answer 4

b,\(\frac{17}{13}\)-(\(\frac{4}{13}\)-11)

=\(\frac{17}{13}\)-\(\frac{4}{13}\)+11

=1+11=12

Answer 5

c,\(\frac{3}{5}\).\(\frac{18}{17}\)+\(\frac{3}{5}\).\(\frac{9}{17}\)-\(\frac{3}{5}\).\(\frac{10}{17}\)

=\(\frac{3}{5}\).(\(\frac{18}{17}\)+\(\frac{9}{17}\)-\(\frac{10}{17}\))

=\(\frac{3}{5}\).1=\(\frac{3}{5}\)