= 1/2 - 1/4 + 1/4 - 1/6 + 1/6 - 1/8 +......+ 1/2014 - 1/2016

= 1/2 - 1/2016

= 1008/2016 - 1/2016

= 1007/2016

không chắc lắm!!!

\(\frac{2}{2.4}+\frac{2}{4.6}+\frac{2}{6.8}+...+\frac{2}{2014.2016}\)

=\(\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+\frac{1}{6}-\frac{1}{8}+...+\frac{1}{2014}-\frac{1}{2016}\)

<=>\(\frac{1}{2}-\left(-\frac{1}{2016}\right)=\frac{1}{2}+\frac{1}{2016}=\frac{1009}{2016}\)

Hôm qua mình thi gặp bài này tắc tịt lun nè

Gọi A = 2/2*4 + 2/4*6 + 2/6*8 + ....................+ 2/2014*2016

A = 1/2 - 1/4 + 1/4 - 1/6 + 1/6 -1/8 + .... + 1/2014 - 1/2016

Rút gọn ta được : A = 1/2 - 1/2016 = 1008 - 1 /2016 = 1007 / 2016

=> A = 1007/2016

thank

\(\frac{2}{2.4}+\frac{2}{4.6}+\frac{2}{6.8}+....+\frac{2}{2014.2016}\)

\(=\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+......+\frac{1}{2014}-\frac{1}{2016}\)

\(=\frac{1}{2}-\frac{1}{2016}\)

\(=\frac{1008}{2016}-\frac{1}{2016}=\frac{1007}{2016}\)

\(\frac{2}{2\times4}+\frac{2}{4\times6}+...+\frac{2}{2014\times2016}\)

=\(\left(\frac{2}{2}-\frac{2}{4}\right)+\left(\frac{2}{4}-\frac{2}{6}\right)+...+\left(\frac{2}{2014}-\frac{2}{2016}\right)\)

=\(\frac{2}{2}-\frac{2}{4}+\frac{2}{4}-\frac{2}{6}+...+\frac{2}{2014}-\frac{2}{2016}\)

=\(\frac{2}{2}-\frac{2}{2016}=\frac{1007}{1008}\)

\(\frac{2}{2.4}+\frac{2}{4.6}+\frac{2}{6.8}+....+\frac{2}{2014.2016}\)

\(=\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+\frac{1}{6}-\frac{1}{8}+...+\frac{1}{2014}-\frac{1}{2016}\)

\(=\frac{1}{2}-\frac{1}{2016}=\frac{1008}{2016}-\frac{1}{2016}=\frac{1007}{2016}\)

11,66865276

Ô! Hay nhỉ! Thú vị thật.

Ta co : 2/2*4+2/4*6+2/6*8+.....+2/2014*2016

         =1/2-1/4+1/4-1/6+1/6-1/8...+1/2014-1/2016

         =1/2-1/2016=1007/2016

2/2 x 4 + 2/2 x 6 +2/6 x 8 + ...................... +2/2014 x 2016

=2/2 - 2/4 +2/2 -2/6 + 2/6 +2/8 + .................+2/2014 - 2/2016

rut gon ta duoc con lai: 2/2-2/2016

=1-1/1008

=1007/1008

tk minh nha

chuc ban hoc tot

happy valentine's day

dap an cua ban sai roi do dap an la 1007/1008

chị kết bạn với em nha gửi lời kết bn với em nhé

j zậy em hả 

\(A=\left[1+\left(-2\right)\right]+\left[3+\left(-4\right)\right]+....+\left[2013+\left(-2014\right)+2015\right]\)

\(A=\left(-1\right)+\left(-1\right)+....+\left(-1\right)+2015\left(\text{1007 số hạng }\left(-1\right)\right)=1008\)

\(B=\left(-2\right)+4+\left(-6\right)+8+\left(-10\right)+,...+\left(-2014\right)+2016\)

\(B=2+2+....+2\left(\text{504 số hạng 2}\right)=1008\)

c) 1 + ( -3 ) +5 + ( -7 ) + ...........+ 2013 + ( -2015 )

[ 1 + (-3 ) ] + [ 5 + -7 ] + .......... + [ 2013 + ( - 2015 ) ]

 có số cặp là : [ ( 2015 - 1 ) : 2 + 1 ] : 2 = 504 ( cặp )

= -2 + -2 + -2 +..........+ -2

= -2 x 504

= -1008