a, - { -(2016 +2015) - [ - (2016 - 2015) - (2016+2015) ] }

= -{-(2016+2015)-[-0-0]}

= -{-4031-0-0}

=-4031

a)\(=\frac{2017}{2016}.\frac{3}{4}-\frac{1}{2016}.\frac{3}{4}\)

\(=\frac{3}{4}\left(\frac{2017}{2016}-\frac{1}{2016}\right)\)

\(=\frac{3}{4}.1\)

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

b)\(=\frac{2015}{2016}\left(\frac{1}{2}+\frac{1}{3}-\frac{5}{6}\right)\)

\(=\frac{2015}{2016}.0\)

\(=0\)

a =1/2016 + 3/2016+5/2016+...+2015/2016

=(1+2015)/ 2016 + (3+2013)/2016 +...+(1007 + 1009)/2016 (504 cap so)

=2016/2016+2016/2016+...+2016/2016(504 phan so)

=1+1+1+...+1(504 so)

=504

504 đấy!

=504 nha ban

C) 540

\(\frac{1}{2016}\)+ \(\frac{3}{2016}\)+ \(\frac{5}{2016}\)+..........+ \(\frac{2015}{2016}\)= \(\frac{1+3+5+....+2015}{2016}\)

                                                                                         =\(\frac{1016064}{2016}\)= \(504\)

\(\frac{1}{2016}\)\(+\frac{3}{2016}\)\(+\frac{5}{2016}\)\(+...+\frac{2015}{2016}\)

\(=\frac{1+3+5+...+2015}{2016}\)

\(=\frac{1016064}{2016}\)

\(=504\)

Ta có :A=\(\frac{1}{2016}+\frac{2}{2016}+...+\frac{2015}{2016}=\frac{1+2+...+2015}{2016}\)

Xét 1+2+ ... +2015 = \(\frac{2015\times2016}{2}=2031120\)---> A=\(\frac{2031120}{2016}=1007,5\)

=(1+2+3+...+2015)/2016=(2015.(2015+1):2)/2016=2031120/2016=2015/2

\(A=\frac{1}{2016}+\frac{2}{2016}+\frac{3}{2016}+...+\frac{2015}{2016}\)

\(A=\frac{1+2+3+...+2015}{2016}=\frac{2031120}{2016}=\frac{2015}{2}\)

2015/2

Tk mình đi mọi người mình bị âm nè!

Ai tk mình mình tk lại cho

Bài 1 : 

a) 40/49 > 15/21

b) 22/49 > 3/8

c) 25/46 < 12/18